Method of scattering fine particles, method of manufacturing liquid crystal display, apparatus for scattering fine particles, and liquid crystal display

ABSTRACT

The present invention has its object to provide a method of spraying particles by which predetermined quantities of particles can be disposed on specified electrodes, in particular a method of spraying particles by which spacers can be sprayed in interelectrode gaps selectively even in the case of substrates comprising pattern-forming transparent electrodes, such as those used in liquid crystal display devices, and a method of producing liquid crystal display devices of high contrast and high display uniformity by which spacers can be disposed in interelectrode gaps without sacrificing the aperture ratio and by which spacers can be disposed on the substrate without irregularity to attain a uniform cell thickness over the whole substrate, as well as a particle spraying apparatus and a liquid crystal display device.  
     The present invention provides a method of spraying particles  
     which comprises applying a voltage of the same polarity as the particle charge polarity to a plurality of electrodes formed on a substrate  
     and spraying the particles while utilizing the repulsive force operating on the particles,  
     wherein means is employed for preventing the particles from being forced out of the electrode domain comprising the plurality of electrodes.

TECHNICAL FIELD

[0001] The present invention relates to a method of spraying particles,a method for producing a liquid crystal display device, a particlesprayer and a liquid crystal display device.

BACKGROUND ART

[0002] With the advancement of electronic technology, particles havebeen put to wide, practical use in various fields. Among such particles,there maybe mentioned particles used as spacers in liquid crystaldisplay devices, for instance.

[0003] In one of the fields of application of such particles, liquidcrystal display devices, for instance, are widely used in personalcomputers, portable electronic apparatus and the like. Generally, aliquid crystal display device comprises, as shown in FIG. 75, a liquidcrystal layer 7 sandwiched between two paired insulating substrates 1,on which color filters 4, a black matrix 5, transparent electrodes 3, analignment layer 9 and so on are formed.

[0004] The distance between the above paired insulating substrates 1,namely the thickness of the liquid crystal layer, influences thetransmittance of light and, therefore, if the liquid crystal layerthickness is not maintained constant all over the display area of aliquid crystal display device, satisfactory display will not beattained. For this reason, spacers 8, for example glass fibers or trulyspherical plastic beads, are disposed between the paired insulatingsubstrates so that the liquid crystal layer thickness may be maintainedconstant all over the display area.

[0005] These spacers are dispersed uniformly on the alignment layer, forexample, by spraying, together with a compressed gas, from a nozzle (dryspraying) or spraying of a liquid composed of spacers and a volatileliquid (wet spraying) after alignment layer formation. Thereafter, theinsulating substrate is paired with a counterpart insulating substratefor panel alignment and a liquid crystal, for example a nematic liquidcrystal, is filled into the space between the paired insulatingsubstrates with spacers sandwiched therebetween.

[0006] When, however, spacers are disposed also on pixel electrodeswithin the display area, light leakage occurs from such spacers and thesubstantial aperture ratio is thereby reduced, so that such problems asdisplay unevenness and reduced contrast arise.

[0007] For solving such problems as mentioned above, it is onlynecessary to dispose spacers only in those electrode gaps which arenondisplay areas, namely only at sites of a black matrix, which isconstituted of a light shield layer. The black matrix is provided forthe purpose of improving the display contrast of the liquid crystaldisplay device and, in the case of TFT type liquid crystal displaydevices, for the purpose of preventing their elements from erroneouslyoperating in response to external light.

[0008] For TFT type liquid crystal display devices, a technology ofdisposing spacers at sites corresponding to the black matrix, namely atsites other than display pixel sites, is disclosed in Japanese KokaiPublication Hei-04-256925 which comprises maintaining the gate electrodeand drain electrode at the same electric potential in the step ofspraying spacers. Further, Japanese Kokai Publication Hei-05-61052discloses a method comprising applying a positive voltage to the circuitelectrodes and charging spacers negatively and spraying them by drymethod. In these technologies, it is intended to control spacerdisposition by applying a voltage to electrodes formed on the substrate.

[0009] However, they have a problem. Namely, application of a voltage tothe substrate having thin film transistors (TFTs) formed thereon, forthe purpose of controlling the spacer disposition, may lead todestruction of elements by that voltage, hence to failure to function asa liquid crystal display device.

[0010] There is another problem. Namely, such technologies as mentionedabove cannot be employed in STN (supertwisted nematic) type liquiddisplay devices since the sites corresponding to the black matrix arespaces among transparent electrodes.

[0011] On the other hand, as a technology of disposing spacers in spacesbetween stripe-form transparent electrodes constituted by disposing aplurality of linear transparent electrodes in parallel on a substrate,as in STN type liquid crystal display devices, there are disclosed, inJapanese Kokai Publication Hei-03-293328 and Japanese Kokai PublicationHei-04-204417, methods of producing liquid crystal display devices whichcomprise charging spacers either positively or negatively and applying avoltage of the same polarity to the transparent electrodes on thesubstrate in the step of spacer spraying.

[0012] In particular, according to Japanese Kokai PublicationHei-04-204417, a conductor is disposed below the electrode substrate ina spacer sprayer for positive voltage application so that the velocityof falling of negatively charged spacers may be controlled. It isfurther disclosed that, for avoiding adhesion of negatively chargedspacer particles to the wall of the spray chamber, the chamber should bemade of a conductor to enable negative voltage application.

[0013] However, when, in practicing these methods, the spacer chargeamount and/or the voltage to be applied to electrodes is selected at alow level (voltage value: not higher than about 1,000 V), the repulsiveforce (repellent force) between spacers and electrodes becomes weak, andthe force for shifting spacers to interelectrode spaces becomesinsufficient, hence the selectivity toward spacer disposition inelectrode-free areas (interelectrode areas) becomes poor, with theresult that a number of spacers are disposed also on each electrode, asshown in FIG. 76.

[0014] Conversely when the spacer charge amount and/or the voltage to beapplied to electrodes is increased (voltage value: about severalkilovolts), the repulsive force between spacers and electrodes becomesstrong and the selectivity toward spacer disposition in electrode-freeareas (interelectrode areas) is improved, as shown in FIG. 77.

[0015] In this case, however, the repulsive force acts more stronglyover the set of electrodes, so that the tendency of spacers to be turnedout of the domain of the electrodes increases; as a result, no spacersare disposed at all in the peripheral region of the electrode domain,hence the cell thickness cannot be controlled in the peripheral regionof the electrode domain. Although such phenomenon occurs already at astate at which the repulsive force is still weak, the area ofspacer-free portions unfavorably and markedly increases as the repulsiveforce increases.

[0016] In Japanese Kokai Publication Hei-08-76132, there is disclosed amethod of disposing spacers more selectively as compared with themethods mentioned above. The method comprises charging spacers to besprayed either positively or negatively, applying a voltage opposite inpolarity of the spacer charge to first electrodes provided in areas onthe insulating substrate where spacers are to be disposed, and applyinga voltage of the same polarity as the spacer charge polarity to secondelectrodes provided in areas on the insulating substrate where nospacers are to be disposed, to thereby apply a repulsive force and anattractive force between spacers and the electrodes so that the spacersmay be disposed either on the first electrodes or on the secondelectrodes with good selectivity.

[0017] This method, however, has a problem in that the contrast isdecreased by the occurrence of spacers on the electrodes. Anotherproblem is that when this method is applied to the production of simplematrix type liquid crystal display devices, it is necessary to formelectrodes for spacer disposition in addition to the pixel electrodesand the aperture ratio decreases accordingly.

SUMMARY OF THE INVENTION

[0018] Accordingly, it is an object of the present invention to solvethe above problems and provide a method of spraying particles by whichpredetermined quantities of particles can be disposed on specifiedelectrodes, in particular a method of spraying particles by whichspacers can be sprayed in interelectrode gaps selectively even in thecase of substrates comprising pattern-forming transparent electrodes,such as those used in liquid crystal display devices, and a method ofproducing liquid crystal display devices of high contrast and highdisplay uniformity by which spacers can be disposed in interelectrodegaps without sacrificing the aperture ratio and by which spacers can bedisposed on the substrate without irregularity to attain a uniform cellthickness over the whole substrate, as well as a particle sprayingapparatus and a liquid crystal display device.

[0019] In a first aspect, the present invention provides a method ofspraying particles

[0020] which comprises applying a voltage of the same polarity as theparticle charge polarity to a plurality of electrodes formed on asubstrate

[0021] and spraying the particles while utilizing the repulsive forceoperating on the particles,

[0022] wherein means is employed for preventing the particles from beingforced out of the electrode domain comprising the plurality ofelectrodes.

[0023] In a second aspect, the invention provides a method for producinga liquid crystal display device comprising

[0024] spraying spacers onto at least one of a first substratecomprising at least pattern-forming transparent electrodes and having atleast one display area and a second substrate to be disposed opposedlyabove the first substrate

[0025] and filling a liquid crystal into the space between both thesubstrates,

[0026] wherein accessory electrodes are provided outside the displayarea

[0027] and, in spraying positively or negatively charged spacers ontothe substrate, two or more voltages differing in voltage value areapplied to respective transparent electrodes

[0028] and a voltage is applied to the accessory electrodes as well tothereby control the electric field generated above the transparentelectrodes and above the accessory electrodes so as to cause selectivespacer disposition only in a predetermined transparent electrode gapamong the gaps between respective neighboring transparent electrodes.

[0029] In a third aspect, the invention provides a method for producinga liquid crystal display device comprising

[0030] spraying spacers onto at least one of a first substratecomprising at least pattern-forming transparent electrodes and a dummyelectrode and a second substrate to be disposed opposedly above thefirst substrate

[0031] and filling a liquid crystal into the space between both thesubstrates,

[0032] wherein, in spraying positively or negatively charged spacersonto the substrate, two or more voltages differing in voltage value areapplied to respective transparent electrodes and a voltage is applied tothe dummy electrode as well,

[0033] the predetermined transparent electrode gaps in which spacers areto be selectively disposed are provided between respective twoneighboring transparent electrodes,

[0034] the number of transparent electrodes is even,

[0035] and the two or more voltages differing in value are applied in amanner such that when the spacer charge polarity is positive (+), thelowest of the two or more voltages differing in value is applied to therespective two neighboring transparent electrodes between which spacersare to be disposed in the middle,

[0036] and when the spacer charge polarity is negative (−), the highestof the two or more voltages differing in value is applied to therespective two neighboring transparent electrodes between which spacersare to be disposed in the middle.

[0037] In a fourth aspect, the invention provides a method for producinga liquid crystal display device comprising

[0038] spraying spacers onto at least one of a first substratecomprising at least pattern-forming transparent electrodes and a dummyelectrode and a second substrate to be disposed opposedly above thefirst substrate

[0039] and filling a liquid crystal into the space between both thesubstrates,

[0040] wherein, in spraying positively or negatively charged spacersonto the substrate, the substrate is disposed in close contact with anearthed conductive stage,

[0041] a conductor is provided in a state electrically insulated fromthe conductive stage,

[0042] said conductor being a conductive frame having an opening,

[0043] and said conductive frame being disposed on the periphery of thesubstrate with or without partial overlapping with the substrateperiphery,

[0044] and wherein a voltage is applied to the transparent electrodesand the conductive frame.

[0045] In a fifth aspect, the invention provides a method for producinga liquid crystal display device comprising

[0046] spraying spacers onto at least one of a first substratecomprising at least pattern-forming transparent electrodes and analignment layer and having at least one display area and a secondsubstrate to be disposed opposedly above the first substrate

[0047] and filling a liquid crystal into the space between both thesubstrates,

[0048] wherein, in spraying positively or negatively charged spacersonto the substrate, the substrate is disposed in close contact with anearthed conductive stage,

[0049] a voltage having the same polarity as the spacer charge polarityis applied to the transparent electrodes on the substrate,

[0050] a conductor is provided, outside the display area, in a stateelectrically isolated from the conductive stage

[0051] and a voltage having the same polarity as the polarity of thevoltage applied to the transparent electrodes is applied to theconductor to thereby form almost the same electric field within andwithout the substrate.

[0052] In a sixth aspect, the invention provides a method for producinga liquid crystal display device comprising

[0053] spraying spacers onto at least one of a first substratecomprising at least pattern-forming transparent electrodes and analignment layer and having one or more display areas and a secondsubstrate to be disposed opposedly above the first substrate

[0054] and filling a liquid crystal into the space between both thesubstrates,

[0055] wherein, in spraying positively or negatively charged spacersonto the substrate, the substrate is disposed in close contact with anearthed conductive stage smaller in size than the substrate to allow thesubstrate periphery to be apart from the conductive stage

[0056] and a voltage of the same polarity as the spacer charge polarityis applied to the transparent electrodes on the substrate.

[0057] In a seventh aspect, the invention provides a particle sprayerfor disposing charged particles selectively on a substrate having aplurality of electrodes

[0058] which comprises a nozzle for spraying charged particles onto thesubstrate,

[0059] a conductive stage having a fixed position and serving to holdthe substrate onto which charged particles are to be sprayed,

[0060] a plurality of push-up pins for mounting the substrate on anddismounting the substrate from the conductive stage,

[0061] a probe for applying a voltage identical in polarity with thecharged particles to a plurality of electrodes on the substrate disposedon the conductive stage,

[0062] and a conductor being electrically insulated from the conductivestage,

[0063] said conductor being a conductive frame provided with an openingsmaller in size than the substrate,

[0064] and said conductive frame being disposed on the top of thesubstrate disposed on the conductive stage and being applied a voltageof the same polarity as the charged particle polarity thereto.

[0065] In an eighth aspect, the invention provides a liquid crystaldisplay device as obtainable by utilizing the method of sprayingparticles according to the first aspect of the invention.

[0066] In a ninth aspect, the invention provides a liquid crystaldisplay device as obtainable by the method for producing a liquidcrystal display device according to the second or third aspect of theinvention.

[0067] In a tenth aspect, the invention provides a liquid crystaldisplay device as obtainable by the method for producing a liquidcrystal display device according to the fourth, fifth or sixth aspect ofthe invention using the particle sprayer according to the seventh aspectof the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

[0068]FIG. 1 is a schematic sectional view illustrating an equipotentialsurface above the substrate in the prior art method for producing aliquid crystal display device.

[0069]FIG. 2 is a schematic plan view illustrating the relation betweenthe transparent electrodes and dummy electrode formed on the substrate,as seen from above, in the method for producing a liquid crystal displaydevice according to the present invention, wherein the dummy electrodeis connected with the transparent electrodes.

[0070]FIG. 3 is a schematic plan view illustrating the relation betweenthe transparent electrodes and dummy electrode, as seen from above, inthe method for producing a liquid crystal display device according tothe present invention, wherein the dummy electrode is not connected withthe transparent electrodes.

[0071]FIG. 4 is a schematic sectional view illustrating a spacer sprayerto be used in the practice of the present invention.

[0072]FIG. 5 is a sectional view illustrating an electrode patternrelevant to the present invention.

[0073]FIG. 6 is a schematic view illustrating the manner of spacerdisposition as attainable according to the present invention.

[0074]FIG. 7 is a schematic view illustrating the method of disposingspacers by means of a macroscopic electric field according to thepresent invention.

[0075]FIG. 8 is a schematic view illustrating the conventional method ofdisposing spacers by means of a macroscopic electric field.

[0076]FIG. 9 is a schematic view illustrating the regions relativelyhigh in voltage (+ (positive)) and the regions relatively low in voltage(− (negative)) formed above stripe-shaped transparent electrodes, asseen from above the stripe-shaped transparent electrodes.

[0077]FIG. 10 is a schematic view illustrating a trouble encounteredwhen the polarity of the voltage applied to the transparent electrodesis reverse to the spacer charge polarity.

[0078]FIG. 11 is a plan view illustrating the electrode pattern in anembodiment of the present invention.

[0079]FIG. 12 is a plan view illustrating the electrode pattern inanother embodiment of the present invention.

[0080]FIG. 13 is a plan view illustrating the electrode pattern on oneof a pair of insulating substrates in producing two liquid crystaldisplay devices from the pair of insulating substrates in an embodimentof the present invention.

[0081]FIG. 14 is a schematic view illustrating the method of disposingspacers by means of an electric field in the middle of the display areain an embodiment of the present invention.

[0082]FIG. 15 is a schematic view illustrating the method of disposingspacers by means of an electric field in the vicinity of the peripheryof the display area in an embodiment of the present invention.

[0083]FIG. 16 is a schematic view illustrating how spacers move underthe influence of an electric field all over the whole display area in anembodiment of the present invention.

[0084]FIG. 17 is a plan view illustrating the electrode pattern on oneof a pair of insulating substrates in producing two liquid crystaldisplay devices from the pair of insulating substrates in an embodimentof the present invention.

[0085]FIG. 18 is a schematic view illustrating the method of disposingspacers by means of an electric field in the central portion of thedisplay area in an embodiment of the present invention.

[0086]FIG. 19 is a schematic view illustrating the method of disposingspacers by means of an electric field in the vicinity of the peripheryof the display area in an embodiment of the present invention.

[0087]FIG. 20 is a schematic view illustrating how spacers move underthe influence of an electric field all over the whole display area in anembodiment of the present invention.

[0088]FIG. 21 is a schematic view illustrating the method of disposingspacers by means of an electric field in the central portion of thedisplay area in an embodiment of the present invention.

[0089]FIG. 22 is a schematic view illustrating the method of disposingspacers by means of an electric field in the vicinity of the peripheryof the display area in an embodiment of the present invention.

[0090]FIG. 23 is a schematic view illustrating how spacers move underthe influence of an electric field all over the whole display area in anembodiment of the present invention.

[0091]FIG. 24 is a schematic view illustrating the method of disposingspacers by means of an electric field in the central portion of thedisplay area in an embodiment of the present invention.

[0092]FIG. 25 is a schematic view illustrating the method of disposingspacers by means of an electric field in the vicinity of the peripheryof the display area in an embodiment of the present invention.

[0093]FIG. 26 is a schematic view illustrating how spacers move underthe influence of an electric field all over the whole display area in anembodiment of the present invention.

[0094]FIG. 27 is a plan view illustrating the electrode pattern in anembodiment of the present invention.

[0095]FIG. 28 is a plan view illustrating the electrode pattern on oneof a pair of insulating substrates in producing two liquid crystaldisplay devices from the pair of insulating substrates in an embodimentof the present invention.

[0096]FIG. 29 is a schematic view illustrating the method of disposingspacers by means of an electric field in the central portion of thedisplay area in an embodiment of the present invention.

[0097]FIG. 30 is a schematic view illustrating the method of disposingspacers by means of an electric field in the vicinity of the peripheryof the display area in an embodiment of the present invention.

[0098]FIG. 31 is a schematic view illustrating how spacers move underthe influence of an electric field all over the whole display area in anembodiment of the present invention.

[0099]FIG. 32 is a plan view illustrating the electrode pattern in anembodiment of the present invention.

[0100]FIG. 33 is a schematic view illustrating the method of disposingspacers by means of an electric field in the central portion of thedisplay area in an embodiment of the present invention.

[0101]FIG. 34 is a schematic view illustrating the method of disposingspacers by means of an electric field in the vicinity of the peripheryof the display area in an embodiment of the present invention.

[0102]FIG. 35 is a schematic view illustrating how spacers move underthe influence of an electric field all over the whole display area in anembodiment of the present invention.

[0103]FIG. 36 is a schematic view illustrating the method of disposingspacers by means of an electric field in the central portion of thedisplay area in an embodiment of the present invention.

[0104]FIG. 37 is a schematic view illustrating the method of disposingspacers by means of an electric field in the vicinity of the peripheryof the display area in an embodiment of the present invention.

[0105]FIG. 38 is a schematic view illustrating how spacers move underthe influence of an electric field all over the whole display area in anembodiment of the present invention.

[0106]FIG. 39 is a schematic view illustrating the high and low voltagestates in the practice of the present invention.

[0107]FIG. 40 is a schematic view illustrating a trouble resulting fromspacer movements caused by an electric field all over the display areain the prior art.

[0108]FIG. 41 is a schematic view illustrating a trouble resulting fromspacer movements caused by an electric field all over the display areain the prior art.

[0109]FIG. 42 is a schematic view of a comb-shaped electrode to be usedin an embodiment of the method for producing a liquid crystal displaydevice according to the present invention.

[0110]FIG. 43 is a schematic view illustrating the method for producinga liquid crystal display device according to the present invention.

[0111]FIG. 44 is a schematic view of a substrate provided with dummyelectrodes which is to be used in an embodiment of the method forproducing a liquid crystal display device according to the presentinvention.

[0112]FIG. 45 is a schematic view of a substrate provided with dummyelectrodes which is to be used in an embodiment of the method forproducing a liquid crystal display device according to the presentinvention.

[0113]FIG. 46 is a schematic view illustrating the relation among thefirst substrates, stage and conductive frame in an embodiment of themethod for producing a liquid crystal display device according to thepresent invention, the top figure being a plan view seen from above andthe bottom being a sectional view.

[0114]FIG. 47 is a schematic view illustrating the relation among thefirst substrates, stage and conductive frame in an embodiment of themethod for producing a liquid crystal display device according to thepresent invention, the top figure being a plan view seen from above andthe bottom being a sectional view.

[0115]FIG. 48 is a schematic side view illustrating how spacers aresprayed onto the first substrate in an embodiment of the method forproducing a liquid crystal display device according to the presentinvention.

[0116]FIG. 49 is a schematic sectional view illustrating a method ofapplying a voltage from the conductive frame to the dummy electrode inan embodiment of the method for producing a liquid crystal displaydevice according to the present invention, wherein a needle terminal(probe) projects out from a flat surface facing the substrate on theconductive frame to the dummy electrode for voltage application andwherein the needle terminal (probe) is provided on the connecting planeconnecting the conductive frame with the dummy electrode.

[0117]FIG. 50 is a schematic sectional view illustrating a method ofapplying a voltage from the conductive frame to the dummy electrode inan embodiment of the method for producing a liquid crystal displaydevice according to the present invention, wherein a needle terminal(probe) projects out from a flat surface facing the substrate on theconductive frame to the dummy electrode for voltage application andwherein the needle terminal (probe) has a certain length and connects aside of the conductive frame and a side of the dummy electrode.

[0118]FIG. 51 is a schematic side view illustrating how spacers aresprayed onto the first substrate in an embodiment of the method forproducing a liquid crystal display device according to the presentinvention.

[0119]FIG. 52 is a schematic sectional view illustrating theequipotential surface over the substrate when the stage is not earthed.

[0120]FIG. 53 is a schematic sectional view illustrating theequipotential surface over the substrate in the method for producing aliquid crystal display device according to the present invention.

[0121]FIG. 54 is a schematic sectional view illustrating theequipotential surface over the substrate in the method for producing aliquid crystal display device according to the present invention.

[0122]FIG. 55 is a schematic view, inclusive of a plan view andsectional views, illustrating the relation between the substrate and theconductive frame in the method for producing a liquid crystal displaydevice according to the present invention.

[0123]FIG. 56 is a schematic sectional view illustrating the case wherethe conductive stage and conductive frame are formed in isolation fromeach other on an insulator in practicing the method for producing aliquid crystal display device according to the present invention.

[0124]FIG. 57 is a schematic sectional view illustrating the relationbetween the conductive stage and conductive frame in the method forproducing a liquid crystal display device according to the presentinvention, with a substrate end portion being shown on exaggeratedscale.

[0125]FIG. 58 is a schematic sectional view illustrating the relationbetween the conductive stage and conductive frame in the method forproducing a liquid crystal display device according to the presentinvention, with a substrate end portion being shown on exaggeratedscale.

[0126]FIG. 59 is a schematic view, inclusive of a plan view and asectional view, illustrating the picture frame-like state of the blackmatrix in the method for producing a liquid crystal display deviceaccording to the present invention.

[0127]FIG. 60 is a schematic sectional view illustrating the relationbetween the conductive stage and conductive frame in the method forproducing a liquid crystal display device according to the presentinvention, with a substrate end portion being shown on exaggeratedscale.

[0128]FIG. 61 is a schematic sectional view illustrating the relationbetween the substrate and stage in the prior art method for producing aliquid crystal display device.

[0129]FIG. 62 is a schematic sectional view illustrating the relationbetween the substrate and stage in the method for producing a liquidcrystal display device according to the present invention.

[0130]FIG. 63 is a schematic sectional view illustrating theequipotential surface over the substrate in the method for producing aliquid crystal display device according to the present invention.

[0131]FIG. 64 is a schematic sectional view illustrating an example ofthe particle sprayer according to the present invention.

[0132]FIG. 65 is a schematic sectional view illustrating the feeding andcarrying-out of the substrate in the sprayer shown in FIG. 64.

[0133]FIG. 66 is a schematic sectional view illustrating, on exaggeratedscale, the essential elements shown in FIG. 64.

[0134]FIG. 67 is a schematic plan view illustrating the relation betweenthe substrate and conductive frame in the particle sprayer according tothe present invention.

[0135]FIG. 68 is an explanatory drawing showing an equipotential lineobtainable upon application of a voltage to the conductive frame and tothe transparent electrodes in the particle sprayer according to thepresent invention.

[0136]FIG. 69 is a plan view showing the electrodes on the insulatingsubstrate in an embodiment of the present invention.

[0137]FIG. 70 is a schematic sectional view showing a liquid crystaldisplay device according to the present invention.

[0138]FIG. 71 is a schematic view illustrating the method for producinga liquid crystal display device according to the present invention.

[0139]FIG. 72 is a schematic sectional view illustrating a method ofvoltage application to the dummy electrode in an embodiment of themethod for producing a liquid crystal display device according to thepresent invention.

[0140]FIG. 73 is a schematic sectional view of the spacer sprayer usedin an embodiment of the method for producing a liquid crystal displaydevice according to the present invention.

[0141]FIG. 74 is a schematic sectional view of the spacer sprayer usedin another embodiment of the method for producing a liquid crystaldisplay device according to the present invention.

[0142]FIG. 75 is a schematic sectional view of a prior art liquidcrystal display device.

[0143]FIG. 76 is a schematic view illustrating the prior art spacerdisposition characteristics.

[0144]FIG. 77 is a schematic view illustrating the prior art spacerdisposition characteristics.

EXPLANATION OF CODES

[0145]1—insulating substrate (glass substrate)

[0146]2—polarizer

[0147]3, 3 a, 3 b—display electrode (linear transparent electrode, pixelelectrode)

[0148]4—color filter layer

[0149]5—conductive black matrix

[0150]6—overcoat layer

[0151]7—liquid crystal

[0152]8—spacer

[0153]9—alignment layer

[0154]10—chamber (sprayer itself)

[0155]10 a—cover

[0156]11 a—nozzle

[0157]11 b—particle tank

[0158]12—voltage application apparatus (direct current source)

[0159]13—spacer metering (dosing) feeder

[0160]14—insulator

[0161]15—conductive stage (stage, electrode).

[0162]16—parting line

[0163]17—pipeline (spacer blowing out tube)

[0164]18, 18 a, 18 b—conductor

[0165]19—conducting part

[0166]19 a—conducting wire (A)

[0167]19 b—conducting wire (B)

[0168]20, 20 a, 20 b—auxiliary electrode

[0169]21—dummy electrode

[0170]22—display electrode area

[0171]23—insulation layer

[0172]24—sealing material

[0173]25—spacer within sealing

[0174]26—black matrix picture frame

[0175]27—transparent conductive layer

[0176]28—dummy electrode area

[0177]29, 29 a, 29 b—accessory electrode

[0178]30—display area

[0179]31—driving mechanism

[0180]32—robot mechanism

[0181]32 a—arm

[0182]32 b—sucking cup

[0183]33—spacer spraying range

[0184]34—conductive frame (field, repulsive force field)

[0185]34 a—opening

[0186]34 b—push-up shaft

[0187]35—probe (needle terminal)

[0188]36—push-up pin

[0189]37—equipotential line (equipotential surface)

DISCLOSURE OF THE INVENTION

[0190] In the following, the present invention is described in detail.

[0191] The method of spraying particles according to the first aspect ofthe present invention comprises applying a voltage of the same polarityas the particle charge polarity to a plurality of electrodes formed on asubstrate and spraying the particles while utilizing the repulsive forceoperating thereon,

[0192] wherein means is employed for preventing the particles from beingturned out of the electrode domain comprising the plurality ofelectrodes.

[0193] The above substrate maybe made of glass, a resin, a metal or anyother appropriate material and has a plurality of electrodes on itssurface. Its shape is not particularly restricted; thus, it may besubstrate-like or film-shaped, for instance. When a metal substrate isused, however, it is necessary to provide an insulating layer on themetal substrate to prevent the electrodes formed on its surface fromshort-circuiting.

[0194] The above electrodes include, but are not limited to, transparentelectrodes, linearized transparent electrodes (linear transparentelectrodes) and so on. As the substrate on which the above plurality ofelectrodes are formed, there may be mentioned substrates comprisingpattern-forming transparent electrodes, among others. The abovesubstrate comprising pattern-forming transparent electrodes is, forexample, a substrate having stripe electrodes constituted from lineartransparent electrodes disposed in parallel. The stripe electrodes areused as the so-called display electrodes in liquid crystal displaydevices. The electrode region comprising the above plurality ofelectrodes is the region where the plurality of electrodes form aelectrodes group and, when the plurality of electrodes are used asdisplay electrodes, the region is the display electrode area. In liquidcrystal display devices, the region for performing displaying out of theabove display electrode-forming region is called display area.

[0195] In cases where the above method of spraying particles is used inthe production of liquid crystal display devices, the above substrateincludes, among others, color filter substrates having a black matrix,color filters, an overcoat layer, pattern-forming transparent electrodesand an alignment layer, and substrates having a black matrix, anovercoat layer, pattern-forming transparent electrodes and an alignmentlayer. The substrate onto which spacers are to be sprayed may be asubstrate having a color filter or a substrate to face such substrate asmentioned above.

[0196] Therefore, when the above method of spraying particles is appliedto the production of STN type liquid crystal display devices, the methodis applicable to any substrate, whether it is a common electrode(scanning electrode) substrate or a segment electrode (displayelectrode) substrate, on condition that it has pattern-formingtransparent electrodes at the least.

[0197] The particles are not particularly restricted but include, forexample, metal particles; synthetic resin particles; inorganicparticles; light-shielding particles of a synthetic resin containing apigment dispersed therein; particles colored with a dye; particlesexhibiting adhesiveness upon application of heat or light, for instance;and particles derived from metal particles, synthetic resin particles,inorganic particles or the like by plating the surface thereof with ametal. They are generally used as spacers in liquid crystal displaydevices. The spacers serve to adjust the cell thickness in liquidcrystal display devices.

[0198] The above method of spraying particles may be dry method or wetmethod. In the wet spraying method, particles are sprayed in the form ofa dispersion in a mixed solvent composed of water and an alcohol, forinstance. Even in this case, the particles can be charged and,therefore, the effects of the first aspect of the invention will not bereduced. The dry method of spraying is proffered, however, since theamount of charge can be stabilized in the dry spraying.

[0199] In the above dry method of spraying, the particles can becharged, for example, by repetitions of their contacting with a pipelineor by application a voltage thereto. Among these, the method comprisingpassing particles through a pipeline by means of such a medium ascompressed air or compressed nitrogen can charge the particles in astable manner. In that case, the moisture content in the medium gasshould preferably be as low as possible from the viewpoint of particlecharging and preventing moisture adhesion to the substrate.

[0200] The material of the pipeline may be a metal or a resin and canadequately be selected in connection with the particle charge polarityand the amount of charge.

[0201] The metallic pipeline includes, but is not particularly limitedto, pipelines made of a single material such as nickel, copper, aluminumor titanium; and pipelines made of an alloy such as stainless steel,among others. It may be a pipeline having a metallic coating, such as agold or chromium coating, formed by plating, for instance, on thepipeline inside wall.

[0202] The resin-made pipeline includes, but is not particularly limitedto, pipelines made of Teflon, a vinyl chloride resin, nylon or the like.For attaining stable charging, however, it is necessary to coat such aresin pipeline with a metal and thereby earth the pipeline. This isbecause if the pipeline is not earthed, the resin pipeline will have anaccumulated charge, which makes it impossible to attain stable charging,since electric charge exchanging occurs as a result of contacting of theparticles with the pipeline.

[0203] For adjusting the amount of charge on the particles, a pluralityof such pipelines differing in material may be connected in series.

[0204] When, in spraying particles, the particle charge polarity is thesame as that of the voltage applied to the plurality of electrodes onthe substrate, for example when the particle charge polarity is positive(+) and the voltage applied to the plurality of electrodes is alsopositive (+), then the total number of particles sprayed onto thesubstrate becomes smaller and more stable than the case of omitting thevoltage application to the plurality of electrodes.

[0205] In the peripheral portions of the substrate where the pluralityof electrodes are absent, however, no repulsive force operates and thoseparticles in the vicinity of the periphery of the substrate are expelledout of the substrate. As a result, the number of particles in portionsaround the region comprising the plurality of electrodes becomesinsufficient. If such technique is applied in the production of liquidcrystal display devices using spacers as the particles, the cellthickness will become reduced in such portions of the device asmentioned above and this may possibly lead to occurrence of displayunevenness.

[0206] In that case, a step of imposing a certain load on liquid crystaldisplay devices is included in the process of liquid crystal displaydevice production. If some or other portions of the substrate show anirregular or fluctuating number of spacers, the load per spacer variesand the spacer distortion varies accordingly, hence the cell thicknessvaries, in those portions, possibly leading to uneven display on theliquid crystal display devices.

[0207] The cause of such increase or decrease in the number of particlesin the vicinity of the periphery of the region comprising a plurality ofelectrodes may be explained for the case of liquid crystal displaydevice production, as follows. As shown in FIG. 1, when spacers areintended to be disposed in transparent electrode gaps by applying avoltage of the same polarity as the spacer charge polarity to thepattern-forming transparent electrodes, a force (repulsive force)repelling falling spacers out of the display area from within thedisplay area operates and, in particular in the vicinity of theperiphery of the display area, there is no repulsive force above thesubstrate region outside the region comprising the plurality oftransparent electrodes and therefore particles to be disposed in theperipheral portions of the display area escape to the outside or, whenthe region outside the display area is wide and large, those particlesare sprayed concentratedly onto the region outside the display area.

[0208] Accordingly, the method of spraying particles according to thefirst aspect of the invention comprises

[0209] applying a voltage of the same polarity as the particle chargepolarity to a plurality of electrodes formed on a substrate

[0210] and spraying the particles while utilizing the repulsive forceoperating on the particles,

[0211] wherein means is employed for preventing the particles from beingturned out of the electrode domain comprising the plurality ofelectrodes.

[0212] In particular, even when the amount of particle charge and/or thevalue of the voltage to be applied to the plurality of electrodes isincreased for improving the selectivity of disposition in interelectrodegaps, an action is produced to prevent particles from being forced outof the electrode domain comprising the plurality of electrodes, so thatparticles are sprayed and disposed in those interelectrode spaces aswell which occur in the edge portions of the electrode domain comprisingthe plurality of electrodes.

[0213] In carrying out the above method of spraying particles, it ispreferred that a dummy electrode be provided outside the electrodedomain comprising a plurality of electrodes and a voltage of the samepolarity as the particle charge polarity be applied also to the dummyelectrode to thereby control the electric field above the periphery ofthe electrode domain comprising the plurality of electrodes.

[0214] Thus, by applying a voltage of the same polarity as the particlecharge polarity to the dummy electrode and adjusting the voltage tothereby control the electric field, it becomes possible to cause arepulsive force to operate on particles and thus push back thoseparticles otherwise expelled out of the electrode domain comprising aplurality of electrodes to the inside of the electrode domain, with theresult that particles are sprayed and disposed also in thoseinterelectrode spaces which occur in the edge portions of the electrodedomain comprising the plurality of electrodes.

[0215] Further, if the voltage applied to the dummy electrode isadjusted properly, it is also possible to control the density ofdisposed particles. In other words, it becomes possible to correctmacroscopic deviations in the electric field in the edge portions of theelectrode domain comprising a plurality of electrodes by applying avoltage to the dummy electrode as well.

[0216] Furthermore, by adjusting the voltage applied to the dummyelectrode, it also becomes possible to intentionally control the numberof particles to be disposed in the edge portions of the electrode domaincomprising a plurality of electrodes and, by applying the first aspectof the present invention to the production of liquid crystal displaydevices, it becomes possible to adjust the cell thickness in the edgeportions (in the vicinity of sealed portions) of the electrode domaincomprising a plurality of electrodes.

[0217] The dummy electrode includes within the scope thereof, but is notlimited to, conductive electrodes formed and disposed outside theelectrode domain (electrode group) comprising a plurality of electrodes,such as those mentioned below. Any other known appropriate dummyelectrodes may also be used effectively.

[0218] In Japanese Kokai Publication Sho-63-266427, there are discloseddummy electrodes which have the same state as in the displayelectrode-forming parts and are provided for the purpose of improvingthe quality of the display part having the same color as the backgroundcolor by eliminating color, unevenness resulting from gap irregularitybetween the substrates and to which no display voltage is applied.

[0219] The dummy electrodes are provided between the stripe-shapeddisplay electrodes made of a transparent conductive material such as ITOas provided on the upper substrate and the sealed portions formed on theperiphery of the upper substrate. The dummy electrodes make the gapsbetween the display part and sealed portions identical in state with thedisplay part.

[0220] When they are formed simultaneously with the display electrodes,the dummy electrodes can be made of the same material and can have thesame thickness as the display electrodes. However, no display voltage(signal voltage) is applied to the dummy electrodes. On the lowersubstrate, like on the upper substrate, dummy electrodes are formedbetween the display electrodes and sealed portions.

[0221] In Japanese Kokai Publication Hei-02-301724, there are disclosedtransparent electrodes (dummy electrodes) provided for the purpose ofenabling the production of liquid crystal panels having a uniform liquidcrystal layer thickness.

[0222] Among the dummy electrodes provided on the upper and lowersubstrates, the dummy electrode provided on the upper substrate facesthe dummy electrode on the lower substrate on the left side and baseside of the nondisplay area and, on the upper side, a transparentelectrode forming the display area. Among the nondisplay area, on theright side, a dummy electrode on the lower substrate faces a transparentelectrode on the upper substrate.

[0223] Therefore, transparent electrodes face to each other in all partsof the nondisplay area. As a result, a liquid crystal panel having auniform liquid crystal layer thickness, which is determined by the gapmaterial diameter, can be obtained.

[0224] In Japanese Kokai Publication Hei-03-260624, there are discloseddummy electrodes provided around segment electrodes at a distance of 1to 5 μm from the segment electrodes for the purpose of preventing thegeneration of static electricity during rubbing treatment in the step ofrubbing treatment, which is to be followed by cutting off the dummyelectrodes.

[0225] The dummy electrodes are intended to provide liquid crystaldevices having high display quality by preventing the alignment layerfrom being disturbed by static electricity in dot matrix type liquidcrystal devices produced by providing segment electrodes and commonelectrodes derived respectively from transparent electrode layers on apair of substrates, further providing an alignment layer on eachelectrode layer and causing a liquid crystal to be sandwiched betweenthe substrates.

[0226] Thus, by providing dummy electrodes at sites surrounding thesegment electrodes on the substrate with a segment electrode-to-dummyelectrode distance of 1 to 5 μm, it is possible to eliminate staticelectricity emanation between segment electrodes in the step of rubbing.A liquid crystal display device showing no color irregularity can beobtained by cutting off the dummy electrodes after rubbing treatment.

[0227] In Japanese Kokai Publication Hei-06-51332, there is disclosed adummy electrode provided in a matrix type liquid crystal display devicefor the purpose of eliminating color irregularity at extractionelectrode sites outside the pixel region.

[0228] The dummy electrode is provided for rendering the thickness ofthe outside of the pixel region identical with the liquid crystal layerthickness in the pixel region.

[0229] The above dummy electrode may be formed outside the display areaon the substrate for preventing the alignment layer from being damagedby sparking caused by static electricity in the process for producingSTN type liquid crystal display devices. For example, when two displaysubstrates having stripe-shaped transparent electrodes are to bemanufactured from one substrate, it is provided around each displayarea, as shown in FIG. 2 or FIG. 3. FIG. 2 is for the case of the dummyelectrode being connected with the transparent electrodes and, FIG. 3 isfor the case of the dummy electrode being not connected with them.

[0230] The above method of spraying particles is preferably carried outby applying a voltage of 500 to 8,000 V to the plurality of electrodes.

[0231] As a result of the voltage applied being controlled, therepulsive force operating between the particles and electrodesincreases, the selectivity in particle disposition in electrode gaps isimproved accordingly, and the particles are sprayed onto the edgeportions of the electrode domain comprising the plurality of electrodesas well with good disposition characteristics without the particlesbeing expelled out of the electrode domain comprising the plurality ofelectrodes.

[0232] In carrying out the method of spraying particles according to thefirst aspect of the invention, a voltage of the same polarity as theparticle charge polarity is preferably applied to an electrode otherthan the plurality of electrodes which occurs on the substrate and atleast partly surrounding the electrode domain comprising the pluralityof electrodes.

[0233] The electrode other than the plurality of electrodes, which isthe dummy electrode, is formed on the substrate having the plurality ofelectrodes formed thereon, and always serves to correct the unbalancedelectric field formed above the substrate by the plurality ofelectrodes, irrespective of the position of setting of the substrate inthe particle sprayer. Since the plurality of electrodes and the dummyelectrode are formed on the substrate, it is not necessary to modify thesetting of the particle sprayer according to the substrate size and/orthe difference in the voltage applied to the electrodes. This is anadvantage from the industrial viewpoint.

[0234] In carrying out the method of spraying particles according to thefirst aspect of the invention, it is preferred that the electrode otherthan the plurality of electrodes be provided in the peripheral regionexclusive of an auxiliary electrode site for applying a voltage to theplurality of electrodes.

[0235] For example, when the plurality of electrodes are stripe-shapedelectrodes, an auxiliary electrode (solid electrode) for applying avoltage to said electrodes is provided at one end or both ends of thestripe-shaped electrodes, and the electric field irregularity iscorrected by the auxiliary electrode (solid electrode). Therefore, themeans for preventing particles from being forced out of the electrodedomain comprising a plurality of electrodes is preferably providedparticularly at a site where there is no auxiliary electrode.

[0236] In the method of spraying particles according to the first aspectof the invention, the electrode other than the plurality of electrodespreferably has an area larger than the area of each of the plurality ofelectrodes.

[0237] Thus, when the electrode area is increased, the repulsive forceoperating on particles increases. By selecting a larger dummy electrodearea than that of each of the plurality of electrodes, a greater actionis produced to turn back particles to the electrode domain comprisingthe plurality of electrodes; as a result, particles are more efficientlydisposed also in interelectrode gaps at the edge portions of theelectrode domain comprising the plurality of electrodes.

[0238] In carrying out the method of spraying particles according to thefirst aspect of the invention, the one and same voltage is preferablyapplied to the plurality of electrodes and to the electrode other thanthe plurality of electrodes.

[0239] If, for example, patterning is carried out so as to causeelectric short-circuiting in forming the plurality of electrodes and thedummy electrode, it is unnecessary to newly provide an electric wire orthe like for applying a voltage to the dummy electrode, and it isunnecessary, too, to newly and separately prepare a means for voltageapplication to the dummy electrode; this is advantageous from theindustrial viewpoint.

[0240] In the method of spraying particles according to the first aspectof the invention, it is preferred that the electrode other than theplurality of electrodes be a solid electrode provided in the peripheralregion of the substrate.

[0241] Thus, by applying a voltage to the solid electrode (meshelectrode) provided in the peripheral region of the substrate foreliminating the height difference, it becomes possible to produce theeffects of the first aspect of the present invention using theconventional designing standard without increasing the number of steps.

[0242] In that case, any electrode, for example a solid, mesh or blockelectrode, may be employed as the electrode for applying a voltage tothe region outside the electrode domain comprising a plurality ofelectrodes.

[0243] Referring to FIGS. 4 to 8, typical embodiments of the firstaspect of the invention are now described.

[0244]FIG. 4 is a schematic view showing a spacer sprayer to be used inan embodiment of the first aspect of the present invention. On the topof a tightly closed or substantially closed clean vessel 10, there isprovided a nozzle 11 a for spraying charged spacers 8. A feeder (notshown) for feeding spacers 8 and nitrogen gas is connected with thenozzle 11 a via a pipeline 17. Under the vessel 10, there is disposed aninsulating substrate 1 made of glass or the like and having displayelectrodes 3 formed thereon, and there is also provided an electric wire18 for applying a voltage to the display electrodes 3 for electric fieldformation. It is also possible to form an electric field by means of astage (electrode) 15 provided within the spacer sprayer in lieu ofelectric field formation by voltage application to the displayelectrodes 3.

[0245] In the production of liquid crystal display devices, the sprayingof spacers 8 is generally carried out by charging an appropriatequantity of spacers by the charging method mentioned above, in this casecharging spacers negatively, and causing them to be sprayed onto thesubstrate by means of compressed air, compressed nitrogen or the like.

[0246]FIG. 5 and FIG. 6 each is a schematic view showing an electrodepattern relevant in the first aspect of the invention. As shown in FIG.5, stripe-shaped display electrodes 3 and dummy electrodes 21, which arepositioned outside the display area and to which a voltage is to beapplied, are formed on an insulating substrate 1. Means (not shown) forvoltage application to the respective electrodes are also provided. Themeans for voltage application may be auxiliary electrodes formed forvoltage application to the display electrodes 3, or voltage applicationto the display electrodes 3 may be directly performed by applying probepins to the respective electrodes.

[0247] Since the electrode domain comprising a plurality of electrodes(display electrode area) is charged in general (macroscopically)negatively, a repulsive force (solid line) operates against spacers andthe spacers tend to move (escape) out of the display electrode area tothe outside region where there is no electric field. Nevertheless, byapplying a negative voltage to the dummy electrodes 21, it is possible,as shown in FIG. 6, to dispose spacers with certainty also in displayelectrode gaps in the display electrode end portions otherwise causing atendency toward spacer escaping.

[0248] The solid lines in FIG. 6 schematically show the magnitudes ofthe repulsive force exerted on spacers in terms of “upwardly convex”semicircles. FIG. 6 shows the manner of shifting and disposition ofcharged spacers to and in repulsive force valleys.

[0249]FIG. 7 and FIG. 8 each is a schematic view illustrating howspacers move under the influence of a macroscopic electric field formedon the electrode substrate. The display electrode area is as a whole(macroscopically) charged negatively and therefore, in the case of FIG.8, a repulsive force is exerted on spacers and the spacers tend to beturned out of the display electrode area to the region where no electricfield is formed. Here, by applying a negative voltage to the dummyelectrodes 21, it becomes possible to turn back the spacers and disposethe spacers also in predetermined display electrode gaps in the displayelectrode end portions to thereby maintain the predetermined spacerdensity in the display electrode end portions and in the middle portionsof the display electrodes.

[0250] While the method of electric field control mentioned abovereferring to the above embodiment is based on the provision of dummyelectrodes 21 on the substrate having display electrodes formed thereon,another method is also available which comprises applying a voltage tothe stage on which the substrate having display electrodes formedthereon is fixed or to the wall of the spacer sprayer to thereby producethe same effects. However, when dummy electrodes for controlling theelectric field are disposed on the stage on which the insulatingsubstrate is set, or on the wall of the particle sprayer, it becomesnecessary to position the insulating substrate at a location equivalentin relation to the dummy electrodes provided outside the insulatingsubstrate. This is unfavorable from the industrial viewpoint.

[0251] When dummy electrodes are provided on the wall of the particlesprayer and when the insulating substrate is a dual panel one from whichtwo liquid crystal display devices are to be excised, the intendedeffect is not produced along the neighboring sides of the two panels.

[0252] Furthermore, when dummy electrodes are provided outside theinsulating substrate, the distance from the display electrode areaincreases, hence it becomes necessary to apply, to the dummy electrodes,a voltage much higher than the voltage conventionally applied to theelectrodes. This is unfavorable from the industrial viewpoint.

[0253] On the other hand, by controlling the voltage applied to thedummy electrode according to the first aspect of the invention, itbecomes possible to control also the density of spacers disposed in theperipheral portions of the display area and to exactly control thesubstrate cell thickness, which depends on the spacer dispositiondensity.

[0254] While the above embodiment is concerned with a simple matrix typeliquid crystal display device, the first aspect of the present inventionis applicable not only to such simple matrix type liquid crystal displaydevice but of course also to such liquid crystal display devices asferroelectric liquid crystal display devices or TFT type liquid crystaldisplay devices.

[0255] In producing liquid crystal display devices by applying themethod of spraying particles according to the first aspect of theinvention, it is possible, by applying a voltage to an electrode (dummyelectrodes) outside the display area so that a repulsive force mayoperate on spacers (particles), to form an electric field which pushesback spacers, which tend to move out of the display electrode area, bythe macroscopic potential gradient (gradient of magnitude of repulsiveforce) above the periphery of the display electrode area; it is nowpossible to dispose spacers even in interelectrode gaps in the displayelectrode end portions, where spacer disposition is difficult to attain,with a high probability, hence it is possible to provide higher qualityliquid crystal display devices. It is also possible to control thedensity of spacers disposed in the peripheral portions of the displayarea and thus provide liquid crystal display devices still more higherin display quality.

[0256] The method for producing a liquid crystal display deviceaccording to the second aspect of the invention comprises

[0257] spraying spacers onto at least one of a first substratecomprising at least pattern-forming transparent electrodes and having adisplay area and a second substrate to be disposed opposedly above thefirst substrate

[0258] and filling a liquid crystal into the space between both thesubstrates,

[0259] wherein accessory electrodes are provided outside the displayarea

[0260] and, in spraying positively or negatively charged spacers ontothe above substrate, two or more voltages of different levels areapplied to respective transparent electrodes,

[0261] and a voltage is applied to the accessory electrodes as well tothereby control the electric field generated above the transparentelectrodes,

[0262] and above the accessory electrodes so as to cause selectivespacer disposition only in predetermined transparent electrode gapsamong the gaps between respective neighboring transparent electrodes.

[0263] The above-mentioned pattern-forming transparent electrodes,substrate, spacers and spacer charging method are the same as explainedabove in relation to the first aspect of the invention.

[0264] In applying the method for producing a liquid crystal displaydevice according to the second aspect of the invention to the productionof TFT type liquid crystal display devices, transparent electrode-freeareas are formed on the color filter substrate, which is a commonelectrode substrate, by etching or the like at sites just below theblack matrix portions and then spacers are disposed on the substrate bythe method for producing a liquid crystal display device according tothe second aspect of the invention. Although the common electrodesubstrate in an ordinary TFT type liquid crystal display device has asolid electrode, even etched area-carrying transparent electrodes can bedriven in the same manner as in ordinary TFT type liquid crystal displaydevices by applying the same voltage to the respective electrodes.

[0265] In accordance with the second aspect of the invention, accessoryelectrodes are provided outside the display area and, in sprayingcharged spacers, two or more voltages differing in value are applied therespective transparent electrodes and a voltage is applied to theaccessory electrodes as well to control the electric field generatedabove the transparent electrodes and above the accessory electrodes andthereby control the repulsive force or attractive force exerted oncharged spacers or the repulsive and attractive forces exerted on suchspacers so as to create the trough of a synthetic repulsive force, thecrest of a synthetic attractive force, or the crest of an attractiveforce synthesized from a repulsive force and an attractive force in eachof predetermined transparent electrode gaps among the gaps betweenrespective neighboring transparent electrodes for selective spacerdisposition only in the predetermined transparent electrode gaps.

[0266] The voltage to be applied to the electrodes is not particularlyrestricted in kind but, for example, a direct current voltage, a pulsevoltage may properly be used.

[0267] The manner of applying the two or more voltages differing invalue to the respective transparent electrodes is based on a certainapplication pattern, such that the places, at which the electric fieldformed on the basis of two or more voltages differing in value asapplied to the respective transparent electrodes exerts the strongestattractive force and/or the weakest repulsive force on spacers,correspond to the positions of the transparent electrode gaps.

[0268] The places at which the strongest attractive force is exerted arethose places among the crests of a synthetic attractive force or thecrests of an attractive force synthesized from a repulsive force and anattractive force as formed in the predetermined transparent electrodegaps among the gaps between respective neighboring transparentelectrodes at which the attractive force acts most strongly, while theplaces at which the weakest repulsive force is exterted are those placesamong the troughs of a synthetic repulsive force or the troughs of arepulsive force synthesized from a repulsive force and an attractiveforce as formed in the predetermined transparent electrode gaps amongthe gaps between respective neighboring transparent electrodes at whichthe repulsive force acts most weakly.

[0269] Here, when spacers are intended to be disposed in transparentelectrode gaps by merely applying a voltage of the same polarity as thespacer charge polarity to the pattern-forming transparent electrodes inspraying spacers, a force (repulsive force) repelling falling spacersfrom the display area to the outside of the display area acts, as shownin FIG. 1, in the substrate end portions where no transparent electrodeexists, as explained in detail hereinabove referring to the first aspectof the invention; in particular, in the vicinity of the periphery of thedisplay area, there is no repulsive force above the substrate outsidethe display area, so that spacers to be disposed in the peripheralportions of the display area escape outside or, when the region outsidethe display area is wide, spacers are sprayed concentratedly in theregion outside the display area, with the result that only aninsufficient number of spacers are present in the peripheral portions ofthe display area, hence the cell thickness of the liquid crystal displaydevice produced becomes reduced in those portions, which may possiblylead to display unevenness or irregular display on the liquid crystaldisplay device.

[0270] On the other hand, when an electric field exerting an attractiveforce above the transparent electrodes is utilized, a phenomenon of theelectric field extending to the portions where no electrode existsoccurs, as shown in FIG. 10, since there is an extended electric fieldon the periphery of the substrate. Therefore, when a voltage reverse inpolarity to the spacer charge is applied to the transparent electrodes,an attractive force acts, thus a force drawing sprayed and fallingspacers inwardly from the outside of the display area acts and aphenomenon occurs that the number of spacers increases in the outermostregion larger than the number in the display area.

[0271] To prevent the above two phenomena illustrated by FIG. 1 and FIG.10, a voltage is applied to the accessory electrodes provided outsidethe display area in accordance with the second aspect of the invention,so that a repulsive or attractive force can be exerted on spacers fromoutside the display area, whereby spacers can be prevented from goingout of the display area or coming in from outside the display area.

[0272] As a result, spacers can be disposed selectively in predeterminedtransparent electrode gaps and the spacer disposition density can becontrolled even in the vicinity of the periphery of the display area asin the central region. Thus, it is possible, in liquid crystal displaydevices, to attain a uniform spacer disposition density within thedisplay area and improve the contrast by preventing light leakage fromspacers without sacrificing the aperture ratio.

[0273] Further, when the predetermined transparent electrode gaps inwhich spacers are to be selectively disposed are provided betweenrespective neighboring transparent electrodes to which the same voltageis applied, the repulsive forces or attractive forces become equalized,said repulsive forces or attractive forces being exerted frompredetermined two neighboring transparent electrodes upon application oftwo or more voltages differing in value to the respective transparentelectrodes, on charged spacers which have moved to the trough of asynthetic repulsive force, the crest of a synthetic attractive force orthe crest of an attractive force synthesized from a repulsive force andan attractive force as exerted on the spacers.

[0274] Thus, in cases where repulsive forces act on spacers, the spacerscan be selectively disposed in each predetermined transparent electrodegap alone with a good probability in a manner such that they are pushedby equal repulsive forces exerted by the corresponding predetermined twoneighboring transparent electrodes and, in cases where attractive forcesact on spacers, in a manner such that they are attracted by equalattractive forces exerted by the corresponding predetermined twoneighboring transparent electrodes.

[0275] Further, when, in cases where spacers are charged positively, thepredetermined transparent electrode gaps in which spacers are to bedisposed selectively are provided between the respective neighboringtransparent electrodes to which the lowest voltage of the two or morevoltages differing in value to be applied to the transparent electrodesis applied and, in cases where spacers are charged negatively, they areprovided between the respective neighboring transparent electrodes towhich the highest voltage of the two or more voltages differing in valueto be applied to the transparent electrodes is applied, the trough of asynthetic repulsive force, the crest of a synthetic attractive force, orthe crest of an attractive force synthesized from a repulsive force andan attractive force can be formed in each predetermined transparentelectrode gap.

[0276] Thus, in the case of positively charged spacers, a repulsiveforce acts on them most weakly when the lowest voltage applied to thepredetermined neighboring transparent electrodes is positive and, whenthe lowest voltage applied to the predetermined neighboring transparentelectrodes is negative, an attractive force acts on them most strongly,so that they move to the gaps between those transparent electrodes towhich the lowest voltage is applied.

[0277] In the case of negatively charged spacers, an attractive forceacts on them most strongly when the highest voltage applied to thepredetermined neighboring transparent electrodes is positive and, whenthe highest voltage applied to the predetermined neighboring transparentelectrodes is negative, a repulsive force acts on them most weakly, sothat they move to the gaps between those transparent electrodes to whichthe highest voltage is applied.

[0278] Therefore, spacers can be disposed selectively in thepredetermined transparent electrode gaps alone with a betterprobability.

[0279] Further, when, in cases where spacers are charged positively, thelowest voltage is of negative polarity or when, in cases these spacersare charged negatively, the highest voltage is of positive polarity,spacers move to the crest of a synthetic attractive force or the crestof an attractive force synthesized from a repulsive force and anattractive force generated between the electrodes constituting thepredetermined transparent electrode gaps, and spacers are furtherattracted by equalized attractive forces exerted by the two neighboringtransparent electrodes.

[0280] Therefore, spacers can be disposed selectively in thepredetermined transparent electrode gaps alone with a higherprobability.

[0281] Further, when the voltage or voltages other than the lowest orhighest one which are applied to transparent electrodes are of the samepolarity as the spacer charge polarity, an attractive force generatedbetween the electrodes constituting the predetermined transparentelectrode gaps and spacers, and a repulsive force generated betweenother electrodes and spacers act on spacers and the spacers are pushedby the repulsive force generated between other electrodes and spacers,and attracted by the attractive force generated between thepredetermined neighboring transparent electrodes, and thus move towardthe crest of an attractive force synthesized from the repulsive forceand attractive force as formed in each predetermined transparentelectrode gap and are further attracted by equalized attractive forcesexerted from the predetermined two neighboring transparent electrodes.

[0282] Therefore, spacers can be disposed selectively in thepredetermined transparent electrode gaps alone with a higherprobability.

[0283] When the voltage for charging spacers and the two or morevoltages applied to the transparent electrodes are of the same polarity,a strong repulsive force is generated between the other electrode(s) andspacers, and a weak repulsive force is generated between thepredetermined neighboring electrodes and spacers, and the spacers arepushed by the strong repulsive force generated between them and theother electrode(s), and move to the trough of a synthetic repulsiveforce exerting between each predetermined transparent gap, and arefurther pushed toward the predetermined transparent electrode gap by therepulsive force, so that the spacers can be disposed selectively in thepredetermined transparent electrode gaps alone with a higherprobability.

[0284] In particular, this constitution makes it possible to disposespacers concentratedly in the middle of each predetermined transparentelectrode gap, since spacers are disposed in the predeterminedtransparent electrode gaps in a manner such that they are pushed by arepulsive force.

[0285] Therefore, the probability of spacers being disposed in edgeportions of the predetermined neighboring transparent electrodes can beminimized.

[0286] In cases where the electric field above the display area as awhole exerts a repulsive force on spacers, the polarity of the voltageapplied to accessory electrodes is selected so that a repulsive forcemay be exerted on spacers and, in cases where the electric field abovethe display area as a whole exerts an attractive force on spacers, thepolarity of the voltage applied to accessory electrodes is selected sothat an attractive force may be exerted on spacers, whereby spacers canbe inhibited from migrating out of the display area by exerting arepulsive force, from outside the display area, on spacers in thevicinity of the edge portions of the display area even when the displayarea as a whole exerts a repulsive force on the spacers and, even whenthe display area as a whole exerts an attractive force on spacers, thespacers occurring outside the display area can be inhibited from cominginto the display area from the outside thereof by exerting an attractiveforce thereon from outside the display area.

[0287] Therefore, it is possible to attain a uniform spacer dispositiondensity even in the vicinity of the periphery of the display area.

[0288] Furthermore, by selecting, as the voltage applied to accessoryelectrodes, the same voltage as that voltage among the two or morevoltages differing in voltage value as applied to the transparentelectrodes, which causes the strongest repulsive force or attractiveforce to exert on spacers, it is possible to exert a sufficientrepulsive or attractive force on spacers to inhibit spacers frommigrating out of and from outside the display area.

[0289] Therefore, it is possible to attain a uniform spacer dispositiondensity even in the vicinity of the periphery of the display area.

[0290] When the above transparent electrodes are stripe-shaped ones, andthe accessory electrodes are disposed along and parallel to the longerside of the transparent electrodes, the migration of spacers can beeffectively suppressed on both longer sides of the stripe-shapedtransparent electrodes, where, among the four sides forming the displayarea, spacers tend to readily migrate out of the display area or comeinto the display area from the outside.

[0291] Therefore, it is possible to attain a uniform spacer dispositiondensity even in the vicinity of the periphery of the display area.

[0292] Further, by providing the accessory electrodes according to anelectrode pattern nearly identical with that of transparent electrodes,it becomes possible not only to form the accessory electrode andtransparent electrodes simultaneously using the same material andthereby simplify the production process but also to produce the sameelectric field above the outside of the display area as that above theinside of the display area and thereby attain a uniform spacerdisposition density within the display area.

[0293] By utilizing, as the accessory electrodes, those dummy electrodesprovided for reducing the level difference caused by the transparentelectrodes, it is possible to realize the second aspect of the inventionwhile applying the conventional electrode patterns.

[0294] Therefore, it is possible to attain a uniform spacer dispositiondensity even in the vicinity of the periphery of the display area.

[0295] Further, by utilizing, as the accessory electrodes, those dummyelectrodes provided for some other purpose and not applying displayvoltage thereto, it is possible to realize the second aspect of theinvention while utilizing the conventional electrode patterns.

[0296] As the above dummy electrodes, there may be mentioned thoseexplained hereinabove referring to the first aspect of the invention.

[0297] Now, referring to FIGS. 11 to 39, typical embodiments of thesecond aspect of the invention are described.

[0298] In the production of liquid crystal display devices, spacerspraying is generally carried out by charging an appropriate quantity ofspacers by the charging method mentioned above, and spraying anddisposing them onto the substrate by means of compressed air, compressednitrogen or the like, as described referring to the first aspect of theinvention.

[0299]FIG. 11 and FIG. 12 each is a schematic view showing an electricpattern to be applicable in the practice of the second aspect of theinvention. As shown in FIG. 11 and FIG. 12, stripe-shaped displayelectrodes 3 a and 3 b, auxiliary electrodes 20 a and 20 b for applyinga voltage to the display electrodes 3 a and 3 b, respectively, andaccessory electrodes 29 provided outside the display area are formed onan insulating substrate 1.

[0300] Conductor wires 18, 18 a and 18 b are connected with theauxiliary electrodes 20 a and 20 b and accessory electrodes 29 forforming an electric field by applying voltages to the auxiliaryelectrodes 20 a and 20 b and accessory electrodes 29. Voltages may beapplied directly to the auxiliary electrodes 20 a and 20 b and accessoryelectrodes 29 by means of probe pins or the like without providing theconductor wires 18, 18 a and 18 b, or voltages may be applied directlyto the display electrodes 3 a and 3 b by means of probe pins or the likewithout providing the auxiliary electrodes 20 a and 20 b.

[0301] The display electrodes 3 a occur in pairs of two neighboringdisplay electrodes. The display electrodes 3 b occur between a pair ofdisplay electrodes 3 a and another pair of display electrodes 3 a. InFIG. 11, one display electrode 3 b occurs and, in FIG. 12, two displayelectrodes 3 b occur.

[0302] As for the accessory electrodes 29, those dummy electrodes whichare formed also in the conventional electrode patterns for reducing thelevel difference caused by the display electrodes and controlling theliquid crystal layer thickness to maintain its uniformity may beutilized as the accessory electrodes 29.

[0303] Those dummy electrodes which are formed in the conventionalelectrode patterns and to which no display voltage is applied may alsoserve as the accessory electrodes 29.

[0304]FIG. 13 is a schematic view showing an electrode pattern for oneinsulating substrate in the production of two liquid crystal displaydevices from a pair of insulating substrates in an embodiment of thesecond aspect of the invention. As shown in FIG. 13, the accessoryelectrodes 29 are disposed only in those areas outside each display area30 as seen in the vertical direction of FIG. 13. This is because theauxiliary electrodes 20 a and 20 b are formed in those areas outsideeach display area 30 as seen in the horizontal direction of FIG. 13, andthe auxiliary electrodes 20 a and 20 b produce the same effect as theaccessory electrodes 29. The auxiliary electrodes 20 b and the accessoryelectrodes 29 are connected with each other by conductors, so that thesame voltage is applied to them.

[0305] By using such an electrode pattern as shown in FIG. 11 andapplying voltages differing in voltage value to the auxiliary electrodes20 a and 20 b and the accessory electrodes 29, negative (−) voltages areapplied to the display electrodes 3 a and 3 b and the accessoryelectrodes 29, wherein the voltage applied to the display electrodes 3 ais relatively higher than that applied to the display electrodes 3 b andthe accessory electrodes 29, as shown in FIGS. 14 to 16. Further,spacers 8 are charged negatively and then sprayed.

[0306] In this way, it is possible to dispose spacers 8 only in eachspace between the paired display electrodes 3 a in a manner such thatspacers 8 can be disposed uniformly in spaces between respective paireddisplay electrodes 3 a throughout the display area including thosespaces between respective paired display electrodes 3 a in the vicinityof the edge portions of the display area 30.

[0307] Thus, as shown in FIG. 14 and FIG. 15, as the sprayed and fallingspacers 8 approach the display electrodes 3 a and 3 b, repulsive forcesbased on the electric fields generated above the display electrodes 3 aand 3 b and the accessory electrodes 29 act on the spacers 8, and eachspacer goes away from the display electrode 3 b or accessory electrode29 each exerting a strong repulsive force on it, and moves toward thenearest pair of display electrodes 3 a generating a weak repulsiveforce. The spacer 8 that has moved to the display electrodes 3 a ispushed by equal repulsive forces respectively exerted by the twoneighboring display electrodes 3 a, and falls between the displayelectrodes 3 a.

[0308] Since the display area 30 as a whole is negatively charged, arepulsive force acts on spacers 8 in the vicinity of each edge portionof the display area 30 and tends to move them outside the display area30, as shown in FIG. 16. This movement of spacers 8 to the outside ofthe display area 30, however, can be prevented since a voltage capableof generating a strong repulsive force is applied to the accessoryelectrodes 29.

[0309] The semicircles in FIG. 14 and FIG. 15 schematically indicaterepulsive forces acting on spacers 8 and the magnitude of each repulsiveforce acting on spacers 8 is represented by the size of the semicircle.The broken line schematically indicates the synthetic repulsive forceacting on spacers 8.

[0310] The semiellipses shown in FIG. 16 schematically indicaterepulsive forces acting on spacers 8.

[0311] In the above embodiment, spacers 8 fall into each space betweentwo neighboring display electrodes 3 a while they are pushed by equalrepulsive forces respectively exerted by the display electrodes 3 a, sothat the spacers 8 can be disposed concentratedly in the middle of eachspace between display electrodes 3 a and thus the probability thatspacers 8 may be disposed on edge areas of the display electrodes 3 acan. be minimized.

[0312]FIG. 17 is a schematic view showing an electrode pattern for oneinsulating substrate in the production of two liquid crystal displaydevices from a pair of insulating substrates in an embodiment of thesecond aspect of the invention. As shown in FIG. 17, the accessoryelectrodes 29 are disposed only in those areas which are outside eachdisplay area 30 as seen in the vertical direction of FIG. 17. This isbecause the auxiliary electrodes 20 a and 20 b are formed in those areaswhich are outside each display area 30 as seen in the horizontaldirection of FIG. 17 and the auxiliary electrodes 20 a and 20 b producethe same effect as the accessory electrodes 29.

[0313] By using such an electrode pattern as shown in FIG. 11 andapplying voltages differing in voltage value to the auxiliary electrodes20 a and 20 b and the accessory electrodes 29, positive (+) voltages areapplied to the display electrodes 3 a and 3 b and the accessoryelectrodes 29, wherein the voltage applied to the display electrodes 3 aand the accessory electrodes 29 is relatively higher than that appliedto the display electrodes 3 b, as shown in FIGS. 18 to 20. Further,spacers 8 are charged negatively and then sprayed.

[0314] In this way, it is possible to dispose spacers 8 only in eachspace between the paired display electrodes 3 a in a manner such thatspacers 8 can be disposed uniformly in spaces between respective paireddisplay electrodes 3 a throughout the display area 30 including thosespaces between respective paired display electrodes 3 a in the vicinityof the edge portions of the display area 30.

[0315] Thus, as shown in FIG. 18 and FIG. 19, as the sprayed and fallingspacers 8 approach the display electrodes 3 a and 3 b, attractive forcesact on the spacers 8, where said attractive forces are exerted by theelectric fields generated above the display electrodes 3 a and 3 b andthe accessory electrodes 29, and each spacer goes away from the displayelectrode 3 b exerting a weak attractive force on it and moves towardthe display electrode 3 a and accessory electrode 29 generating a strongattractive force. The spacer 8 that has moved to the display electrode 3a is attracted by equal attractive forces respectively exerted by thetwo neighboring display electrodes 3 a and falls between the displayelectrodes 3 a.

[0316] Since the display area 30 as a whole is positively charged, anattractive force acts on spacers 8 in the vicinity of each edge portionof the display area 30 and tends to move them into the display area 30from outside the display area 30, as shown in FIG. 20. This movement ofspacers 8 from the outside of the display area 30 into the display area30, however, can be prevented, and the density of spacers 8 disposed inrespective spaces between paired display electrodes 3 a can bemaintained at a predetermined level since a voltage capable ofgenerating a strong attractive force is applied to the accessoryelectrodes 29.

[0317] The semicircles in FIG. 18 and FIG. 19 schematically indicateattractive forces acting on spacers 8 and the magnitude of eachattractive force acting on spacers 8 is represented by the size of thesemicircle. The broken line schematically indicates the syntheticattractive force acting on spacers 8.

[0318] The semiellipses shown in FIG. 20 schematically indicateattractive forces acting on spacers 8.

[0319] By using such an insulating substrate electrode pattern as shownin FIG. 17 and applying, according to such an electrode pattern as shownin FIG. 12, voltages differing in voltage value to the auxiliaryelectrodes 20 a and 20 b and the accessory electrodes 29, a positive (+)voltage is applied to the display electrodes 3 a and a negative (−)voltage to the display electrodes 3 b and the accessory electrodes 29,so that the display area 30 as a whole is charged negatively, as shownin FIGS. 21 to 23. Further, spacers 8 are charged negatively and thensprayed.

[0320] In this way, it is possible to dispose spacers 8 only in eachspace between the paired display electrodes 3 a in a manner such thatspacers 8 can be disposed uniformly in spaces between respective paireddisplay electrodes 3 a throughout the display area 30 including thosespaces between respective paired display electrodes 3 a in the vicinityof the edge portions of the display area 30.

[0321] Thus, as shown in FIG. 21 and FIG. 22, as the sprayed and fallingspacers 8 approach the display electrodes 3 a and 3 b, a repulsive forceand an attractive force act on the spacers 8, where both the forces areexerted by the electric fields generated above the display electrodes 3a and 3 b and the accessory electrodes 29 and each spacer goes away fromthe display electrode 3 b or accessory electrode 29 each exerting arepulsive force on it, and moves toward the display electrode 3 agenerating an attractive force. The spacer 8 that has moved to thedisplay electrode 3 a is attracted by equal attractive forcesrespectively exerted by the two neighboring display electrodes 3 a andfalls between the display electrodes 3 a.

[0322] Since the display area 30 as a whole is negatively charged, arepulsive force acts on spacers 8 in the vicinity of each edge portionof the display area 30, and tends to move them outside the display area30, as shown in FIG. 23. This movement of spacers 8 to the outside ofthe display area 30 can be prevented, however, since a voltage capableof generating a repulsive force is applied to the accessory electrodes29.

[0323] The semicircles in FIG. 21 and FIG. 22 schematically indicaterepulsive forces and attractive forces acting on spacers 8 and themagnitude of each repulsive force acting on spacers 8 is represented bythe size of the semicircle convex as seen from a above and the magnitudeof each attractive force acting on spacers 8 by the size of thesemicircle convex as seen from below. The broken line schematicallyindicates the synthetic repulsive or attractive force acting on spacers8.

[0324] By using such an insulating substrate electrode pattern as shownin FIG. 17 and applying, according to such an electrode pattern as shownin FIG. 12, voltages differing in voltage value to the auxiliaryelectrodes 20 a and 20 b and the accessory electrodes 29, a positive (+)voltage is applied to the display electrodes 3 a and the accessoryelectrodes 20, and a negative (−) voltage to the display electrodes 3 b,so that the display area 30 as a whole is charged positively, as shownin FIGS. 24 to 26. Further, spacers 8 are charged negatively and thensprayed.

[0325] In this way, it is possible to dispose spacers 8 only in eachspace between the paired display electrodes 3 a in a manner such thatspacers 8 can be disposed uniformly in spaces between respective paireddisplay electrodes 3 a throughout the display area 30 including thosespaces between respective paired display electrodes 3 a in the vicinityof the edge portions of the display area 30.

[0326] Thus, as shown in FIG. 24 and FIG. 25, as the sprayed and fallingspacers 8 approach the display electrodes 3 a and 3 b, a repulsive forceand an attractive force act on the spacers 8, where both the forces areexerted by the electric fields generated above the display electrodes 3a and 3 b and the accessory electrodes 29, and each spacer goes awayfrom the display electrode 3 b exerting a repulsive force on it, andmoves toward the display electrode 3 a and accessory electrode 29generating an attractive force. The spacer 8 that has moved to thedisplay electrode 3 a is attracted by equal attractive forcesrespectively exerted by the two neighboring display electrodes 3 a andfalls between the display electrodes 3 a.

[0327] Since the display area 30 as a whole is positively charged, anattractive force acts on spacers 8 in the vicinity of each edge portionof the display area 30 and tends to move them into the display area 30from outside the display area 30, as shown in FIG. 26. This movement ofspacers 8 from the outside of the display area 30 into the display area30, however, can be prevented, and the density of spacers 8 disposed inrespective spaces between paired display electrodes 3 a can bemaintained at a predetermined level since a voltage capable ofgenerating an attractive force is applied to the accessory electrodes29.

[0328]FIG. 27 is a schematic view showing an electrode pattern to beused in the practice of the second aspect of the invention.

[0329]FIG. 28 is a schematic view showing an electrode pattern for oneinsulating substrate in the production of two liquid crystal displaydevices from a pair of insulating substrates in an embodiment of thesecond aspect of the invention. As shown in FIG. 27 and FIG. 28, theaccessory electrodes 29 are disposed outside the display area 30 so asto surround the display area 30.

[0330] The accessory electrodes 29 are each connected with a conductorwire 18 for voltage application to the accessory electrodes 29 forelectric field formation. A voltage may also be applied directly to theaccessory electrodes 29 by means of probe pins or the like withoutproviding such conductor wire 18.

[0331] The display electrodes 3 a occur in pairs of two neighboringdisplay electrodes. The display electrodes 3 b occur between a pair ofdisplay electrodes 3 a and another pair of display electrodes 3 a. InFIG. 27, one display electrode 3 b occurs between two pairs of displayelectrodes 3 a.

[0332] By using such an insulating substrate electrode pattern as shownin FIG. 28 and applying, according to such an electrode pattern as shownin FIG. 27, voltages differing in voltage value are applied to thedisplay electrodes 3 a and 3 b and the accessory electrodes 29, apositive (+) voltage is applied to the display electrodes 3 a, and anegative (−) voltage is applied to the display electrodes 3 b and theaccessory electrodes 29, so that the display area 30 as a whole ischarged negatively, as shown in FIGS. 29 to 31. Further, spacers 8 arecharged negatively and then sprayed.

[0333] In this way, it is possible to dispose spacers 8 only in eachspace between the paired display electrodes 3 a in a manner such thatspacers 8 can be disposed uniformly in spaces between respective paireddisplay electrodes 3 a throughout the display area 30 including thosespaces between respective paired display electrodes 3 a in the vicinityof the edge portions of the display area 30.

[0334] Thus, as shown in FIG. 29 and FIG. 30, as the sprayed and fallingspacers 8 approach the display electrodes 3 a and 3 b, a repulsive forceand an attractive force act on the spacers 8, where both the forces areexerted by the electric fields generated above the display electrodes 3a and 3 b and the accessory electrodes 29, and each spacer goes awayfrom the display electrode 3 b or accessory electrode 29 each exerting arepulsive force on it and moves toward the display electrode 3 agenerating an attractive force. The spacer 8 that has moved to thedisplay electrode 3 a is attracted by equal attractive forcesrespectively exerted by the two neighboring display electrodes 3 a andfalls between the display electrodes 3 a.

[0335] Since the display area 30 as a whole is in a state equivalent tothe state of being negatively charged, a repulsive force acts on spacers8 in the vicinity of each edge portion of the display area 30, and tendsto move them outside the display area 30, as shown in FIG. 31. Thismovement of spacers 8 to the outside of the display area 30 can beprevented, however, since a voltage capable of generating a repulsiveforce is applied to the accessory electrodes 29.

[0336]FIG. 32 is a schematic view showing an electrode pattern to beused in the practice of the second aspect of the invention. As shown inFIG. 32, auxiliary electrodes 20 a and 20 b are formed on an insulatingsubstrate 1 for voltage application respectively to the displayelectrodes 3 a and 3 b and stripe-shaped display electrodes 3 a and 3 b.Further, additional display electrodes 3 a and 3 b are formed outsidethe display area 30 so that the display electrodes 3 a formed outsidethe display area 30 may serve as accessory electrodes 29 a and thedisplay electrodes 3 b formed outside the display area 30 may be servedas accessory electrodes 29 b.

[0337] Conductor wires 18 a and 18 b are connected with the auxiliaryelectrodes 20 a and 20 b for electric field formation by applyingvoltages to the auxiliary electrodes 20 a and 20 b. Voltages may beapplied directly to the auxiliary electrodes 20 a and 20 b by means ofprobe pins or the like without providing the conductor wires 18 a and 18b, or voltages may be applied directly to the display electrodes 3 a and3 b and to the accessory electrodes 29 a and 29 b by means of probe pinsor the like without providing the auxiliary electrodes 20 a and 20 b.

[0338] The display electrodes 3 a occur in pairs of two neighboringdisplay electrodes. The display electrodes 3 b occur between a pair ofdisplay electrodes 3 a and another pair of display electrodes 3 a. InFIG. 32, one display electrode 3 b occurs.

[0339] The accessory electrodes 29 are disposed only in those areasoutside the display area 30 as seen in the vertical direction of FIG.32. This is because the auxiliary electrodes 20 a and 20 b are formed inthose areas outside the display area 30 as seen in the horizontaldirection of FIG. 32, and the auxiliary electrodes 20 a and 20 b producethe same effect as the accessory electrodes 29.

[0340] By applying voltages differing in voltage value to the auxiliaryelectrodes 20 a and 20 b according to such an electrode pattern as shownin FIG. 32, negative (−) voltages are applied to the display electrodes3 a and 3 b and the accessory electrodes 29 a and 29 b in a manner suchthat a relatively higher voltage is applied to the display electrodes 3a and accessory electrodes 29 a as compared with the display electrodes3 b and accessory electrodes 29 b, as shown in FIGS. 33 to 35. Further,spacers 8 are charged negatively and then sprayed.

[0341] In this way, it is possible to dispose spacers 8 only in eachspace between the paired display electrodes 3 a in a manner such thatspacers 8 can be disposed uniformly in spaces between respective paireddisplay electrodes 3 a throughout the display area 30 including thosespaces between respective paired display electrodes 3 a in the vicinityof the edge portions of the display area 30.

[0342] Thus, as shown in FIG. 33 and FIG. 34, as the sprayed and fallingspacers 8 approach the display electrodes 3 a and 3 b, a repulsive forceacts on the spacers 8, where said force is exerted by the electric fieldgenerated above the display electrodes 3 a and 3 b and accessoryelectrodes 29, and each spacer goes away from the display electrode 3 bexerting a strong repulsive force on it, and moves toward the displayelectrode 3 a generating a weak repulsive force. The spacer 8 that hasmoved to the display electrode 3 a is pushed by equal repulsive forcesrespectively exerted by the two neighboring display electrodes 3 a, andfalls between the display electrodes 3 a.

[0343] Since the electrode pattern as a whole is negatively charged, therepulsive force acting on spacers 8 in the vicinity of each edge portionof the electrode pattern tends to move them outside the display area 30,as shown in FIG. 35. Since, however, it is accessory electrodes 29 a and29 b that are located in the vicinity of each edge portion of theelectrode pattern as seen in the vertical direction of FIG. 35, it doesnot matter if no spacer 8 is disposed in the vicinity of the edgeportions of the electrode pattern. In other words, the display area 30is located in the middle of the electrode pattern, so that spacers 8 canbe disposed at a predetermined density in the display area 30.

[0344] By using such an insulating substrate electrode pattern as shownin FIG. 17 and applying, according to such an electrode pattern as shownin FIG. 11, voltages differing in voltage value to the auxiliaryelectrodes 20 a and 20 b and the accessory electrodes 29, a positive (+)voltage is applied to the display electrodes 3 a and 3 b and accessoryelectrodes 29 in a manner such that a relatively higher voltage isapplied to the display electrodes 3 b and accessory electrodes 29 ascompared with the display electrodes 3 a, as shown in FIGS. 36 to 38.Further, spacers 8 are charged positively and then sprayed.

[0345] In this way, it is possible to dispose spacers 8 only in eachspace between the paired display electrodes 3 a in a manner such thatspacers 8 can be disposed uniformly in spaces between respective paireddisplay electrodes 3 a throughout the display area 30 including thosespaces between respective paired display electrodes 3 a in the vicinityof the edge portions of the display area 30.

[0346] Thus, as shown in FIG. 36 and FIG. 37, as the sprayed and fallingspacers 8 approach the display electrodes 3 a and 3 b, a repulsive forceact on the spacers 8, where said force is exerted by the electric fieldgenerated above the display electrodes 3 a and 3 b and accessoryelectrodes 29, and each spacer goes away from the display electrode 3 band accessory electrode 29 both exerting a strong repulsive force on itand moves toward the display electrode 3 a generating a weak repulsiveforce. The spacer 8 that has moved to the display electrode 3 a ispushed by equal repulsive forces respectively exerted by the twoneighboring display electrodes 3 a and falls between the displayelectrodes 3 a.

[0347] Since the display area 30 as a whole is positively charged, arepulsive force acts on spacers 8 in the vicinity of each edge portionof the display area 30, and tends to move them outside the display area30, as shown in FIG. 38. This movement of spacers 8 to the outside ofthe display area 30, however, can be prevented since a voltage capableof generating a strong repulsive force is applied to the accessoryelectrodes 29.

[0348] In the above embodiment, spacers 8 fall into each space betweentwo neighboring display electrodes 3 a while they are pushed by equalrepulsive forces respectively exerted by the display electrodes 3 a, sothat the spacers 8 can be disposed concentratedly in the middle of eachspace between display electrodes 3 a and thus the probability thatspacers 8 may be disposed on edge areas of the display electrodes 3 acan be minimized.

[0349] While several embodiments of the second aspect of the inventionhave been described hereinabove, the second aspect of the invention isnot limited to the embodiments described but the same effects asmentioned above can be produced, with negatively charged spacers 8,based on the relation between relatively higher and lower voltagesaccording to the present invention, as shown in FIG. 39.

[0350]FIG. 39 is a schematic representation of the relation between therelative level of the voltage applied to the display electrodes and themagnitude of the repulsive or attractive force exerted on spacers 8 bythe voltage in the case where spacers 8 are negatively charged.

[0351] The relatively higher or lower voltage and the voltage polarityare shown in terms of + or −, with the earth voltage of 0 V at which norepulsive or attractive force acts on spacers 8 being taken as thereference voltage.

[0352] Thus, according to FIG. 39, +300 V, for instance, is a voltagerelatively lower than +500 V and −300 V is a voltage relatively higherthan −500 V.

[0353] Between a display electrode and a spacer 8 separated by a certaindistance from each other, the electric field formed above the displayelectrode exerts a repulsive force or attractive force upon the spacer 8depending on the polarity of the voltage applied to the displayelectrode. According to FIG. 39, where the spacer 8 has a negativepolarity, a repulsive force is produced when the voltage is of negativepolarity (−) while an attractive force is generated when the voltage isof positive polarity. The magnitude of this repulsive becomes greater asthe voltage shifts to the more negative (−) polarity side while that ofthe attractive force becomes greater as the voltage shifts to the morepositive (+) polarity side.

[0354] Thus, +500 V, for instance, produces a greater attractive forcethan +300 V while −500 V produces a greater repulsive force than −300 V.

[0355] In cases where spacers 8 are charged positively, an attractiveforce is exerted in lieu of a repulsive force and vice versa. Thus, avoltage of negative (−) polarity gives rise to an attractive force whilea voltage of positive (+) polarity gives rise to a repulsive force. And,this attractive force becomes greater as the voltage shifts to the morenegative (−) polarity side, while the repulsive force increases as thevoltage shifts to the more positive (+) side.

[0356] Thus, +500 V, for instance, produces a greater repulsive forcethan +300 V while −500 V produces a greater attractive force than −300V.

[0357] According to the definition of the relative level of voltage asmade herein, a voltage is lower when it is on the more negative (−)polarity side, and a voltage is higher when it is on the more positive(+) polarity side, as shown in FIG. 39, irrespective of the magnitude offorce acting on spacers 8.

[0358] Thus, +500 V is defined as a higher voltage than +300 V, and −500V is defined as a lower voltage than −300 V.

[0359] This definition also applies to cases where spacers 8 are chargedpositively. Thus, +500 V is defined as a higher voltage than +300 V, and−500 V is defined as a lower voltage than −300 V.

[0360] Now, referring to FIG. 40 and FIG. 41, troubles encountered whenno accessory electrodes are provided are explained.

[0361]FIG. 40 is a schematic view showing the state of the display area30 being as a whole charged negatively when no accessory electrodes 29are provided. As shown in FIG. 40, the display area 30 as a whole ischarged negatively, so that when spacers are negatively charged andsprayed, a repulsive force acts on the spacers 8.

[0362] In the middle of the display area 30, spacers 8 are subjected torepulsive forces uniformly from around and therefore the spacers 8undergo only the influence of a local electric field and are disposedbetween the paired display electrodes 3 a. In the vicinity of each edgeportion of the display area 30, however, they undergo a repulsive forcedue to the electric field above the display area 30 as a whole andmigrate to the outside of the display area 30 where no electric field isformed. Thus, a trouble arises that spacers 8 are hardly disposed in apredetermined amount in those display electrode (3 a) gaps in thevicinity of the edge portions of the display area 30.

[0363] On the other hand, FIG. 41 is a schematic view showing the casein which the display area 30 as a whole is charged positively but noaccessory electrodes are provided. As shown in FIG. 41, an attractiveforce acts on spacers 8, when they are charged negatively and sprayed,since the display area 30 as a whole is positively charged.

[0364] In the middle of the display area 30, spacers 8 are subjected toattractive forces uniformly from around and therefore the spacers 8undergo only the influence of a local electric field and are disposedbetween the paired display electrodes 3 a. In the vicinity of each edgeportion of the display area 30, however, they undergo an attractiveforce due to the electric field above the display area 30 as a whole andmigrate from the outside of the display area 30, where no electric fieldis formed to the inside of the display area 30. Thus, a trouble arisesthat spacers 8 are more abundantly than a predetermined amount in thosedisplay electrode (3 a) gaps in the vicinity of the edge portions of thedisplay area 30.

[0365] In the embodiments mentioned above, the electric field iscontrolled by providing accessory electrodes 29 on the insulatingsubstrate having display electrodes formed thereon. There is anothermethod available by which it is also possible to produce the sameeffects, said method comprising providing accessory electrodes 29 on astage for fixing thereon the insulating substrate with displayelectrodes formed thereon or on the wall of the spacer sprayer, andapplying a voltage thereto.

[0366] According to the second aspect of the invention, it is alsopossible to adjust the density of spacers disposed in the vicinity ofthe edge portions of the display area 30 by adjusting the voltageapplied to the accessory electrodes 29, and it is further possible tofinely control the liquid crystal layer thickness of the liquid crystaldisplay device by controlling the space disposition density.

[0367] Furthermore, while, in the above embodiments, simple matrix typeliquid crystal display devices are employed, the second aspect of theinvention is not limited to simple matrix type liquid crystal displaydevices, but can of course be applied to the production of ferroelectricliquid crystal display devices, TFT type liquid crystal display devicesand like liquid crystal display devices as well.

[0368] The method for producing a liquid crystal display deviceaccording to the third aspect of the invention comprises

[0369] spraying spacers onto at least one of a first substratecomprising at least pattern-forming transparent electrodes and a dummyelectrode and a second substrate to be disposed opposedly above thefirst substrate

[0370] and filling a liquid crystal into the space between both thesubstrates,

[0371] wherein, in spraying positively or negatively charged spacersonto the substrate, two or more voltages differing in voltage value areapplied to respective transparent electrodes and a voltage is applied tothe dummy electrode as well,

[0372] the predetermined transparent electrode gaps in which spacers areto be selectively disposed are provided between respective twoneighboring transparent electrodes,

[0373] the number of transparent electrodes is even,

[0374] and the two or more voltages differing in value are applied in amanner such that when the spacer charge polarity is positive (+), thelowest of the two or more voltages differing in value is applied to therespective two neighboring transparent electrodes between which spacersare to be disposed in the middle, and when the spacer charge polarity isnegative (−), the highest of the two or more voltages differing in valueis applied to the respective two neighboring transparent electrodesbetween which spacers are to be disposed in the middle.

[0375] The above transparent electrodes, dummy electrodes, substrate,spacers and spacer charging method are the same as described referringto the first aspect of the invention. The method for producing a liquidcrystal display device according to the third aspect of the inventioncan be applied to the production of TFT type liquid crystal displaydevices, as explained hereinabove referring to the second aspect of theinvention.

[0376] The predetermined transparent electrode gaps in which spacers areto be selectively disposed are those transparent electrode gaps to thetransparent electrodes of which the lowest of the two or more voltagesdiffering in value applied to the transparent electrodes is applied whenspacers are charged positively (+), and the predetermined transparentelectrode gaps are those transparent electrode gaps to the transparentelectrodes of which the highest of the two or more voltages differing invalue applied to the transparent electrodes is applied when spacers arecharged negatively (−).

[0377] When, for example, strong repulsive forces and weak repulsiveforces are arranged regularly as shown in FIG. 14, each trough or crestof a synthetic repulsive force occurs in the middle of a region oftransparent electrodes exerting a weak repulsive force or of a region oftransparent electrodes exerting a strong repulsive force (such a regionas shown in FIG. 9).

[0378] Therefore, in the case of FIG. 14, spacers are disposed in themiddle of weak repulsive forces and therefore it is only necessary thatthe space between transparent electrodes be there. For achieving this,the number of transparent electrodes exerting a weak repulsive forceshould be even; in that case, the centerline of the relevant regioncorresponds to the space between the relevant transparent electrodes.

[0379] Further, when repulsive forces and attractive forces are arrangedregularly as shown in FIG. 22, each trough or crest of the synthesis ofa repulsive force and an attractive force occurs in the middle of aregion of transparent electrodes exerting a repulsive force or of aregion of transparent electrodes exerting an attractive force (such aregion as shown in FIG. 9).

[0380] Therefore, in the case of FIG. 22, spacers are disposed in themiddle of attractive forces and it is only necessary that the centerlinebetween transparent electrodes be there. For achieving this, the numberof transparent electrodes exerting an attractive force should be even;in that case, the centerline of the relevant region corresponds to thespace between the relevant transparent electrodes.

[0381] If, however, the number of transparent electrodes exerting a weakrepulsive force is odd in the case of FIG. 14 or the number oftransparent electrodes exerting an attractive force is odd in the caseof FIG. 22, each location where spacers are disposed occurs on thecenterline of a transparent electrode.

[0382] In cases where the spacer charge polarity is negative (−), thevoltage application to the transparent electrodes is carried out byproviding a common conductor line (A) which is connected with one of thetwo ends of each transparent electrode, to which the highest voltage isto be applied, and applying the highest voltage by means of theconductor line (A), while providing a common conductor line (B) which isconnected with one end, on the opposite side of the one end mentionedabove, of the two ends of each transparent electrode, to which a lowervoltage is to be applied, and applying the lower voltage by means of theconductor line (B) and, in cases where the spacer charge polarity ispositive (+), the voltage application to the transparent electrodes iscarried out by providing a common conductor line (A) which is connectedwith one of the two ends of each transparent electrode to which thelowest voltage is to be applied and applying the lowest voltage by meansof the conductor line (A) while providing a common conductor line (B)which is connected with one end, on the opposite side of the one endmentioned above, of the two ends of each transparent electrode to whicha higher voltage is to be applied and applying the higher voltage bymeans of the conductor line (B).

[0383] For example, by using such comb-shaped electrodes having a 2:1structure as shown in FIG. 42 and applying the highest voltage to theconductor line (A), and a voltage lower than the above voltage to theconductor line (B) when the spacer charge polarity is negative (−), itis possible to dispose spacers in spaces or gaps (a). After spacerdisposition, the conductor lines (A) and (B) are cut off along thedotted lines in the figure, to give stripe-shaped transparentelectrodes.

[0384] As mentioned above, the third aspect of the present inventionmakes it possible to dispose spacers in interelectrode spaces where notransparent electrode exists, namely at sites of within the blackmatrix, by applying, in spacer spraying, two or more voltages differingin value to the pattern-forming transparent electrodes.

[0385] If, in spacer spraying, no voltage is applied to the dummyelectrode and two or more voltages differing in value are simply appliedto the transparent electrodes, respectively, the phenomenon of thenumber of spacers increasing or decreasing in the vicinity of theperiphery of the display area is observed, as detailedly describedhereinbefore referring to the first and second aspects of the presentinvention, and the spacer distortion varies, the cell thickness variesand the display on the product liquid crystal display device becomesuneven, as explained hereinabove referring to the first and secondaspects of the present invention.

[0386] For preventing these phenomena, a voltage is applied to the dummyelectrode as well according the third aspect of the present invention,whereby the irregularities in the number of spacers disposed as observedbetween the inside of the display area and the vicinity of the peripherythereof can be prevented from occurring, hence the irregularities incell thickness caused by the above irregularities can be dissolved. As aresult, liquid crystal display devices uniform in displaycharacteristics can be obtained.

[0387] The dummy electrodes are the same as those mentioned hereinabovereferring to the first aspect of the present invention.

[0388] In the following, mention is made of the voltage application tothe dummy electrodes.

[0389] The voltage to be applied to the dummy electrode is preferablywithin the range between the highest and the lowest of the two or morevoltages differing in value which are applied to the transparentelectrodes. Thus, the number of spaces disposed is caused to decrease orincrease in the dummy electrode sections by extending the electric fieldformed above the transparent electrodes and comprising relatively highvoltage (+ (positive)) and relatively low voltage (− (negative)) regionsto above the dummy electrodes, as shown in FIG. 43. As a result, spacersare disposed uniformly in the display area.

[0390] The voltage application to the dummy electrodes is preferablycarried out by connecting one of the conductor lines (A) and (B) withthe dummy electrodes.

[0391] For example, by connecting the conductor line (B) with the dummyelectrodes, as shown in FIG. 44, it becomes possible to apply the sameelectric potential to the conductor line (B) and the dummy electrodes.While, in the case shown in FIG. 44, the conductor line (B) is formed asan electrode integrated with the dummy electrodes, the conductor line(A) may be formed as an electrode integrated with the dummy electrodesor, further, the conductor line (A) or (B) and the dummy electrodesseparately and independently provided on the substrate may be connectedwith each other by wiring.

[0392] The voltage application to the dummy electrodes can also becarried out by connecting all dummy electrodes formed on the substratewith one another.

[0393] For example, by wiring to thereby connect all dummy electrodesformed on the substrate with one another, as shown in FIG. 45, itbecomes possible to apply the same electric potential to all the dummyelectrodes.

[0394] The method for producing a liquid crystal display deviceaccording to the fourth aspect of the present invention comprises

[0395] spraying spacers onto at least one of a first substratecomprising at least pattern-forming transparent electrodes and a dummyelectrode and a second substrate to be disposed opposedly above thefirst substrate

[0396] and filling a liquid crystal into the space between both thesubstrates,

[0397] wherein, in spraying positively or negatively charged spacersonto the substrate, the substrate is disposed in close contact with anearthed conductive stage,

[0398] a conductor is provided in a state electrically isolated from theconductive stage,

[0399] said conductor being a conductive frame having an opening

[0400] and said conductive frame being disposed on the periphery of thesubstrate with or without partial overlapping with the substrateperiphery,

[0401] and wherein a voltage is applied to the transparent electrode andthe conductive frame.

[0402] The above pattern-forming transparent electrodes, substrate,spacers and spacer charging method are the same as explained referringto the first aspect of the invention. As explained referring to thesecond aspect of the invention, the method for producing a liquidcrystal display device according to the fourth aspect of the inventioncan be applied to the production of TFT type liquid crystal displaydevices.

[0403] In accordance with the fourth aspect of the invention, spacerscan be disposed in electrode gaps, without any trouble in spacerdisposition, even when an electric field exerting a repulsive force isformed above the pattern-forming transparent electrodes by applying avoltage of the same polarity as the spacer charge polarity to thepattern-forming transparent electrodes in a state such that thesubstrate with the black matrix formed thereon is in close contact withthe conductive stage.

[0404] If, here, a voltage is merely applied to the transparentelectrodes, the phenomenon of the number of spacers increasing ordecreasing in the vicinity of the periphery of the display area isobserved, as explained in detail referring to the first and secondaspects of the invention, causing variations in spacer distortion and incell thickness in the production of liquid crystal display devices andcausing uneven display of the liquid crystal display devices.

[0405] It is conceivable that the distribution of spacers in the displayarea and the region outside the display area might be controlled byusing a dummy electrode generally used for preventing the build-up ofstatic electricity on the substrate and applying a voltage of the samepolarity as the transparent electrode polarity to the dummy electrodesto thereby render the repulsive force resulting from the electric fieldabove the substrate uniform all over the substrate. For realizing thismethod, however, it is necessary that the dummy electrodes be presentalso in the outside of the display area to thereby secure a sufficientlywide range for spacer spraying. This is unfavorable from the spaceviewpoint.

[0406] For preventing these phenomena, the substrate is disposed inclose contact with an earthed conductive stage, and a conductor isprovided in a state electrically insulated from the conductive stage inspraying positively or negatively charged spacers according to thefourth aspect of the invention. The conductor is a conductive framehaving an opening and is disposed on the periphery of the substrate withor without partial overlapping with the substrate periphery, and avoltage is applied to the transparent electrode and the conductive frameas well to thereby form an electric field outside the substrate as wellwhich is almost the same as that within the substrate. The range of therepulsive force above the substrate is thereby extended and the risk ofthe number of spacers increasing or decreasing is absorbed in the regionoutside the substrate, so that the display area can become uniform withrespect to the number of spacers.

[0407] The earthed conductive stage preferably has a volume resistancevalue of not more than 1×10¹⁰ Ωcm. When the volume resistance value isin excess of 1×10¹⁰ Ωcm, the whole substrate becomes close in electricpotential to the transparent electrodes, with the result that theaccuracy of spacer disposition becomes poor.

[0408] Since if there is an electrically floating electrode, spacers aresprayed concentratedly thereon, the method of applying a voltage of thesame polarity as the spacer charge polarity to the transparentelectrodes formed on the substrate is preferably carried out by applyingthe voltage to all transparent electrodes to thereby eliminate theoccurrence of such electrically floating electrode.

[0409] The material of the above conductor is not particularlyrestricted but may be, for example, a metal such as aluminum, iron,copper or stainless steel; or a resin rendered conductive by coatingwith a metal or the like. The conductor may be made of a laminateproduced by placing a thin metal foil or sheet, such as aluminum foil orcopper foil, on a resin layer.

[0410] In the case of multipanel substrates for producing a plurality ofliquid crystal panels per glass substrate, the shape of the aboveconductor may be such that it has openings corresponding to therespective display areas.

[0411] The method of insulating the above conductive stage from theconductor is not particularly restricted but, for example, an insulator,such as a resin, may be insulated therebetween, or a space is providedtherebetween for attaining insulation by air.

[0412] The method of voltage application to the substrate is notparticularly restricted but, for example, may be the method comprisingproviding a dummy electrode around the linear transparent electrodes onthe substrate, as shown in FIG. 2, connecting the dummy electrode withthe linear transparent electrodes and carrying out voltage applicationto the dummy electrode via the conductive frame in a state electricallyinsulated from the conductive stage on which the substrate is disposed.The method of voltage application from the conductive frame to the dummyelectrode is not particularly restricted but may be, for example, themethod comprising forming a needle-like body or bodies extending fromthe conductive frame.

[0413] The voltage to be applied to the transparent electrodes on thesubstrate and to the conductive frame preferably has a value of severalhundred to several thousand volts. When the voltage applied to too low,it becomes difficult to control the route of falling of spacers. If thevoltage applied is too high, short-circuiting may occur between thetransparent electrodes and the black matrix when the latter is aconductive one.

[0414] The conductor mentioned above may be made from a flat conductoror from a net-, bar- or wire-like conductor. When it is made from a flatsheet conductor, the sheet maybe processed by perforation or the like toproduce a structure for improving the flow of air.

[0415] Now, referring to FIGS. 46 to 51, specific embodiments of themethod for producing a liquid crystal display device according to thefourth aspect of the invention are described.

[0416]FIG. 46 shows an embodiment of the fourth aspect of the inventionfor dual-panel substrates. A conductive frame is formed on theconductive stage while placing a resin or like insulator identical inthickness to the first substrate. The conductive frame is disposed in astate overlapping with the periphery of the substrate. In this way, theconductive frame overlaps with the periphery of the substrate and can bedisposed without leaving any gap.

[0417] In an embodiment of the fourth aspect of the invention, which isshown in FIG. 47, a conductive frame, which is provided with an openingidentical in shape and size with the substrate, is placed on theconductive stage with an insulator sandwiched therebetween.

[0418] When a voltage of the same polarity as the transparent electrodepolarity is applied to the conductive frame, the range of the repulsiveelectric field is enlarged and the risk of the number of spacersincreasing or decreasing is absorbed in the conductor frame portion,hence the distribution of spacers within the display area becomesuniform.

[0419] The mechanism of disposition of the above conductive stage andconductive frame maybe such that the conductive frame preparedseparately be put on the stage from above or they be hinged together forclosing and opening.

[0420]FIG. 48 shows the state of sprayed spacers in the method forproducing a liquid crystal display device according to the fourth aspectof the invention, wherein repulsive forces are utilized.

[0421] In the case of FIG. 47, for instance, the range of the repulsiveforce-exerting electric field can be enlarged by voltage application toall the stripe-shaped transparent electrodes, dummy electrode(s) andconductive frame and, therefore, the uniformity of the display area canbe improved. The electrode structure to be employed in this case is asshown in FIG. 2 or FIG. 3.

[0422] When the dummy electrode is connected with the transparentelectrodes, it becomes possible to carry out voltage application to thedummy electrode via the conductive frame electrically insulated from theconductive stage on which the substrate is disposed.

[0423] The voltage application to the dummy electrode from theconductive frame can be carried out, for example, by forming aneedle-like body on the flat sheet surface facing the substrate on theconductive frame, on the conductive frame-forming flat sheet or on aside of the conductive frame, as shown in FIG. 49 or FIG. 50.

[0424] In some instances, depending on the distance between theconductive frame and display area, the uniformity may not be securedunless a voltage differing from the voltage applied to the transparentelectrodes is applied to the conductive frame.

[0425] When, for example, repulsive forces are utilized for spacerdisposition and the display area is away from the conductive frame, asshown in FIG. 51, spacers may escape into the space therebetween. Insuch a case, it is necessary to apply, to the conductive frame, avoltage producing a repulsive force stronger than that within thedisplay area to thereby repel spacers oppositely toward the periphery ofthe display area utilizing the repulsive force.

[0426] In accordance with the method according to the fourth aspect ofthe invention which comprises effecting spacer charging and applying avoltage to the transparent electrodes to thereby dispose spacers ininterelectrode gaps, the falling of spacers is controlled by disposing aconductive frame (conducting frame) on the periphery of the substrateand applying a voltage thereto, so that spacers can be disposed all overthe substrate, to give a uniform cell gap and high quality displaycharacteristics without display unevenness.

[0427] After completion of spacer spraying, the above conductive frameis removed and, thereafter, a liquid crystal display device can beproduced by disposing a second substrate opposedly to the firstsubstrate in the conventional manner and filling a liquid crystal intothe space therebetween.

[0428] The method for producing a liquid crystal display deviceaccording to the fifth aspect of the present invention comprises

[0429] spraying spacers onto at least one of a first substratecomprising at least pattern-forming transparent electrodes and analignment layer and having a display area and a second substrate to bedisposed opposedly above the first substrate

[0430] and filling a liquid crystal into the space between both thesubstrates

[0431] wherein, in spraying positively or negatively charged spacersonto the substrate, the substrate is disposed in close contact with anearthed conductive stage,

[0432] a voltage having the same polarity as the spacer charge polarityis applied to the transparent electrodes on the substrate,

[0433] a conductor is provided, outside the display area, in a stateelectrically insulated from the conductive stage,

[0434] and a voltage having the same polarity as the polarity of thevoltage applied to the transparent electrodes is applied to theconductor to thereby form an electric field outside the substrate aswell which is almost the same as the electric field within thesubstrate.

[0435] The above transparent electrodes, substrate, spacers and spacercharging method are the same as those described hereinbefore referringto the first aspect of the invention. The method of liquid crystaldisplay device according to the fifth aspect of the invention can beapplied to the production of TFT type liquid crystal display devices, asexplained hereinabove referring to the second aspect of the invention.

[0436] When, for example, the substrate comprising at leastpattern-forming transparent electrodes and an alignment layer and havingat least one display area is not earthed or is disposed in close contactwith a conductive stage, which is not earthed, as shown in FIG. 52, anda voltage of the same polarity as the charge polarity of charged spacersis applied to the pattern-forming transparent electrodes on thesubstrate in spraying charged spacers, the resulting electric field isnearly uniform (as shown in FIG. 52 as an equipotential surface at acertain electric potential), hence no selective spacer disposition iseffected.

[0437] On the other hand, when the substrate is disposed in closecontact with an earthed conductive stage, as shown in FIG. 53, and avoltage of the same polarity as the charge polarity of charged spacersis applied to the pattern-forming transparent electrodes on thesubstrate, the electric potential lowers above each transparentelectrode gap (as shown in FIG. 53 as a certain equipotential surface ata certain electric potential), hence spacers can be disposed in thetransparent electrode gap under the action of a repulsive force.

[0438] However, in cases where an electric field is formed by thevoltage applied to the pattern-forming transparent electrodes and arepulsive force acts on spacers, the phenomenon of the number of spacersdecreasing in the vicinity of the periphery of the display area isobserved and, as explained referring to the first and second aspects ofthe invention, the spacer distortion becomes varied and the cellthickness varies in the method for producing a liquid crystal displaydevice and the display on the product liquid crystal display devicebecomes uneven.

[0439] The cause of such an increase or decrease in number of spacers inthe vicinity of the periphery of the display area is as follows. Whenspacers are intended to be disposed in transparent electrode gaps byapplying a voltage of the same polarity as the spacer charge polarity tothe pattern-forming transparent electrodes, a force (repulsive force)acts on falling spacers to repel them from within the display area tothe outside of the display area, as shown in FIG. 1, FIG. 52 and FIG.53. In particular, in the vicinity of the periphery of the display area,spacers to be disposed in the peripheral portions of the display areaescape to the outside since there is no repulsive force above thesubstrate portions outside the display area and, when the region outsidethe display area is large, spacers are disposed concentratedly in theregion outside the display area.

[0440] For preventing these phenomena, the fifth aspect of the inventioncomprises disposing, in spraying positively or negatively chargedspacers onto the substrate, the substrate in close contact with anearthed conductive stage, applying a voltage of the same polarity as thespacer charge polarity to the transparent electrode on the substrate,providing, outside the display area, a conductor in a state electricallyinsulated from the conductive stage, and applying a voltage of the samepolarity as that of the voltage applied to the transparent electrodes tothereby form an electric field on the outside of the substrate almostsame as the electric field within the substrate. The result is that therange of the effective repulsive force above the substrate is enlarged,the increase or decrease in number of spacers is absorbed in the regionoutside the substrate, and the number of spacers becomes uniform withinthe display area.

[0441] The earthed conductive stage, the method of applying a voltage ofthe same polarity as the spacer charge polarity to the transparentelectrodes formed on the substrate, the material of the conductor, theshape and size of the conductor, the method of insulating the conductorfrom the conductive stage, the method of voltage application to thesubstrate, the voltage values to be applied to the transparentelectrodes on the substrate and to conductive frame, and the method offorming the conductive frame are the same as those mentioned hereinabovereferring to the fourth aspect of the invention.

[0442] The voltage to be applied to the conductive frame is preferablyapproximately the same as or higher than the voltage applied to thetransparent electrodes. If the voltage applied to the conductive frameis lower than that applied to the transparent electrodes, the decreasein number of spacers on the periphery of the substrate cannot beprevented.

[0443] In cases where different voltages are applied to the conductiveframe and the transparent electrodes, terminals from different voltagesupply apparatus are connected with them, respectively.

[0444] Referring to FIGS. 55 to 60, specific examples of the method forproducing a liquid crystal display device according to the fifth aspectof the invention are now described.

[0445]FIG. 55 is a schematic view illustrating the relation between thesubstrate and conductive frame, in the method for producing a liquidcrystal display device according to the fifth aspect of the invention.In accordance with the fifth aspect of the invention, the conductor is aconductive frame having greater outer dimensions as compared with thesubstrate, as shown in FIG. 55, and has an opening greater in size thanthe display area but smaller in size than the substrate. The conductiveframe is disposed with or without overlapping with the peripheralportions of the substrate, and a voltage of the same polarity as that ofthe voltage applied to the transparent electrodes is preferably appliedto the conductive frame.

[0446] The above conductive stage and conductive frame may be formedeither individually or partitionedly on one and the same insulating flatsheet, as shown in FIG. 56.

[0447] The position where the above conductive frame is to be formed isnot particularly restricted but may be, for example, above the substrateplane, on the same level as the substrate or conductive stage, or belowthe conductive stage.

[0448] In cases where the opening of the conductive frame is smaller insize than the substrate and the conductive frame is placed on thesubstrate, as shown in FIG. 55 (1), or in cases where the opening of theconductive frame is identical with the substrate and the upper surfaceof the conductive frame is on the same level as the substrate surface,as shown in FIG. 55 (2), for instance, no particular problem arises ifthe conductive frame is greater than the substrate and conductive stage;it is only necessary that the insulation of the conductive stage fromthe conductive frame be secured.

[0449] In cases where the opening of the conductive frame is smaller insize than the substrate and the conductive frame is placed on thesubstrate, the conductive frame itself serves as a mask and, therefore,spacers will not be disposed concentratedly in the peripheral region ofthe substrate where there is no transparent electrode.

[0450] In cases where the opening of the conductive frame is identicalin size with the substrate and the upper surface of the conductive frameis on the same level as the substrate surface, however, no repulsiveforce acts above the peripheral region of the substrate where notransparent electrode exists, so that spacers may be disposed on theperipheral region of the substrate in a locally concentrated manner.When the conductive frame is smaller than the conductive stage, spacersmay be disposed in a locally concentrated manner on the protrudingportions of the conductive stage.

[0451] The above local concentration of spacers means the escape ofspacers from the periphery of the display area to the sites ofconcentration. This causes a decrease in number of spacers on theperiphery of the display area and, as a result, the cell thickness maypossibly become irregular in the product liquid crystal display device.

[0452] In cases where the conductive frame is located on the substrate,the substrate can come into full contact with the conductive stage. Thesize of the conductive stage is not particularly restricted but, forexample, may be greater or smaller than the substrate size.

[0453] As regards the spacer disposition, the electric potential aboveeach transparent electrode gap is lowered and an electric field suitedfor the disposition is formed by disposing the substrate into closecontact with the conductive stage. Therefore, in cases where theconductive frame is disposed on the lower (reverse) side of thesubstrate, the conductive frame is in contact with the under (reverse)surface of the substrate, so that the electric potential of thesubstrate in the contact region rises and the spacer disposition qualitymay become poor as the case may be.

[0454] It is preferred that the above conductive stage be not greater insize than the substrate but large enough to cover the region outside theparting lines and the conductive frame upper surface be on almost thesame level as the conductive stage surface, as shown in FIG. 55 (3), orthe conductive frame be disposed at a position lower than the conductivestage, as shown in FIG. 55 (4).

[0455] The parting lines are those lines based on which the first andsecond substrates, after panel alignment, are cut.

[0456] In cases where the dummy electrodes are provided in the regionoutside the display area on the substrate, the region outside theparting lines is the dummy electrode region, as shown in FIG. 59.

[0457] When the conductive frame upper surface is on the almost samelevel as the conductive stage surface, the substrate comes into contactwith the conductive frame, as shown in FIG. 55 (3). When the conductiveframe is disposed at a position lower than the conductive stage, a statearises such that the end portions of the substrate are apart from theframe, as shown in FIG. 55 (4).

[0458] By disposing the conductive frame in such a position, it becomespossible to dispose spacers uniformly in a desired manner all over thesubstrate and prevent spacers from being disposed in a locallyconcentrated manner even in the peripheral portions of the substratewhere no transparent electrode exists, owing to the influence, frombelow, of an electric field formed by the conductive frame.

[0459] It is preferred that the above conductive stage be not greater insize than the substrate but large enough to cover the region outside theparting lines, and the conductive frame be formed outside so as toextend from the region outside the parting lines, to the outside of thesubstrate, as shown in FIG. 57, with the area occupied by the conductivestage and that by the conductive frame in the region outside the partinglines being [area occupied by conductive stage]>[area occupied byconductive frame].

[0460] In the above case, the conductive frame may be disposed incontact with the substrate or out of contact with the substrate.

[0461]FIG. 59 is a schematic view illustrating the picture frame stateof the black matrix, in the method for producing a liquid crystaldisplay device according to the fifth aspect of the invention. At leastone of the first substrate and the second substrate to be disposedopposedly above the first substrate is a color filter substrate forliquid crystal display device production and has a black matrix formedthereon, as shown in FIG. 59. The black matrix is partitioned within thedisplay area to give lattice-forming pixels.

[0462] The above black matrix defines the display area in the manner ofa picture frame. That picture frame state is formed by a region where noblack matrix portion exists. In some instances, the black matrix mayremain as a solid mask or masks also in the dummy electrode portion orportions outside the picture frame. In such cases, the black matrix siteis almost identical with the region comprising transparent electrodes.

[0463] Chromium is most often used as the material for forming the blackmatrix (such black matrix is also called “conductive black matrix). Witha color filter substrate for liquid crystal display device productionhaving such a constitution, even when a conductive stage smaller thanthe region where a black matrix made of chromium is formed, the effectof the earthed conductive stage is obtained in the whole region of theblack matrix and the electric potential of the black matrix is lowered,so that the black matrix region can reflect the effect of the conductivestage.

[0464] Therefore, even when the conductive stage is smaller than thesubstrate, an electric field suited for spacer disposition is formed inthe region occupied by the black matrix.

[0465] When, for forming the picture frame state of the black matrix onthe above substrate, a black matrix-free region is formed, the blackmatrix portion occurring in the display area is separated from the blackmatrix portion or portions in the dummy electrode region or regionsoutside the display area, so that the effect of the earthing of theconductive stage differs between the display area inside and the dummyelectrode region or regions.

[0466] It is therefore necessary that the size of the conductive stagebe such that it covers the picture frame region of the black matrix, theblack matrix-free region and the dummy electrode region or regions. Whenthis requirement is satisfied, the state of spacer disposition on thewhole substrate becomes uniform.

[0467] If, in forming the conductive frame almost on the same level asthe conductive stage, as shown in FIG. 55 (3), the substrate is set onthe conductive frame, the substrate comes into contact with both theconductive stage upper surface and the conductive frame upper surface.

[0468] In that case, the underside (back) of the peripheral region ofthe substrate is locally exposed to the earth potential and an electricpotential from the conductive frame. In particular, in this vicinity,the black matrix within the display area is separated from the blackmatrix in the dummy electrode region or regions, so that the separatedoutside region or regions undergo a unique influence different from theeffect on the display area.

[0469] Therefore, in this case, the separated dummy electrode region orregions should have an electric potential close to the earth potential.For that purpose, it is necessary that, as shown in FIG. 57, the areaoccupied by the conductive stage and that occupied by the conductiveframe within the dummy electrode region or regions be as follows: [areaoccupied by conductive stage]>[area occupied by conductive frame].

[0470] If the relations between the areas occupied by the conductivestage and conductive frame within the dummy electrode region or regionsbecomes [area occupied by conductive stage]<[area occupied by conductiveframe], the electric potential rises in each transparent electrode gapin said region or regions, making spacer disposition difficult.

[0471] It is preferred that the above conductive stage be not greater insize than the substrate but extend to the regions outside the partinglines, and that the conductive frame be formed outside the transparentelectrodes without overlapping with the regions outside the partinglines, as shown in FIG. 58.

[0472] In other words, it is required that the conductive frame beformed at places not included in any dummy electrode region. At suchlocations, the electric potential of the conductive frame will notaffect the black matrix, hence spacers will not be locally concentratedin the peripheral region of the substrate.

[0473] On the other hand, in cases where, among the above-mentionedpositional relations between the conductive stage and conductive frame,the conductive frame is positioned below the conductive stage, theregions outside the parting lines do not directly contact with theconductive frame, as shown in FIG. 55 (4).

[0474] In that case, since the substrate end portions are not earthed,the electric potential rises in those portions and no local spacerconcentration occurs on the substrate end portions.

[0475] In some cases, the material of the above black matrix is made ofa composition comprising a pigment dispersed in a resin, other thanchromium. Since such composition has a low conductivity, the conductivestage may fail, in certain instances, to produce the same effect asproduced in the case of a chromium black matrix.

[0476] When, in such a case, the conductive frame is disposed below thesubstrate, it is preferred that, as shown in FIG. 60, the conductivestage be almost identical in size with the region in which thetransparent electrodes exist, and that the end portions of theconductive frame be formed within the transparent electrode-free region.

[0477] In this manner, the conductive stage is caused to exist in theregion comprising transparent electrodes to form an electric fieldsuited for spacer disposition. On the other hand, the transparentelectrode-free region is caused to contact with the conductive frame orto be free from the conductive stage, to thereby prevent the potentialdrop in the end portions of the substrate and thus prevent spacers frombeing sprayed in a locally concentrated manner.

[0478] By forming a similar electric field above the region outside thedisplay area, as mentioned above, in carrying out the method forproducing a liquid crystal display device according to the fifth aspectof the invention, it becomes possible to dispose spacers uniformly allover the substrate, so that the liquid crystal display device obtainedby that method can have a uniform cell thickness and high qualitydisplay performance characteristics without showing display unevenness.

[0479] The method for producing a liquid crystal display deviceaccording to the sixth aspect of the invention comprises

[0480] spraying spacers onto at least one of a first substratecomprising at least pattern-forming transparent electrodes and analignment layer and having one or more display areas and a secondsubstrate to be disposed opposedly above the first substrate

[0481] and filling a liquid crystal into the space between both thesubstrates,

[0482] wherein, in spraying positively or negatively charged spacersonto the substrate, the substrate is disposed in close contact with anearthed conductive stage smaller in size than the substrate to allow thesubstrate periphery to be apart from the conductive stage,

[0483] and a voltage of the same polarity as the spacer charge polarityis applied to the transparent electrodes on the substrate.

[0484] The above transparent electrodes, substrate, spacers and spacercharging method are not particularly restricted but may be the same asthose mentioned hereinabove referring to the first aspect of theinvention. The method for producing a liquid crystal display deviceaccording to the sixth aspect of the invention can be applied to theproduction of TFT type liquid crystal display devices, as explainedhereinabove referring to the second aspect of the invention.

[0485] If, in practicing the six aspect of the present invention, avoltage of the same polarity as the spacer charge polarity is merelyapplied to the transparent electrodes in spraying spacers, thephenomenon of the number of spacers increasing or decreasing in thevicinity of the periphery of the display area is observed, as explainedin detail referring to the fifth aspect of the invention, and, in theprocess of liquid crystal display device production, the spacers undergodistortion in various ways, causing variations in cell thickness, withthe result that the product liquid crystal display device shows displayunevenness, as explained hereinabove referring to the first and secondaspects of the invention.

[0486] Further, since a voltage of the same polarity as the spacercharge polarity is applied to the transparent electrodes within thesubstrate, a repulsive force acts on spacers above the display area and,on the other hand, since the conductive stage is at the earth potential,an attractive force acts on the charged spacers and, as a result, thosespacers in the peripheral region of the substrate tend to escape fromwithin the substrate by the effects of both of the repulsive force fromwithin the substrate and the attractive force from the conductive stage,as shown in FIG. 61.

[0487] For preventing these phenomena, the sixth aspect of the inventioncomprises, in spraying positively or negatively charged spacers onto thesubstrate, disposing the substrate in close contact with an earthedconductive stage smaller in size than the substrate to thereby maintainthe peripheral region of the substrate apart from the conductive stage,as shown in FIG. 62, and applying a voltage of the same polarity as thespacer charge polarity to the transparent electrodes on the substrate.Thereby, the effect of earthing from the conductive stage upon thesubstrate end portions is weakened, and the electric potential on thetransparent electrodes tends to become rather more influential, so thatthe number of spacers to be disposed in the peripheral portions of thesubstrate can be prevented from decreasing as compared with the case inwhich the conductive stage is greater in size than the substrate.

[0488] The earthed conductive stage, the method of applying a voltage ofthe same polarity as the spacer charge polarity to the transparentelectrodes formed on the substrate, the material of the conductor, theshape and size of the conductor, the method of insulating the conductivestage from the conductor, the method of voltage application to thesubstrate, the voltage values to be applied to the transparentelectrodes on the substrate and to the conductive frame, and the methodof forming the conductive frame are the same as those mentionedhereinabove referring to the fourth aspect of the invention.

[0489] The state of the peripheral region of the substrate being apartfrom the conductive stage is the state in which the edges of thesubstrate are protruding from the conductive stage surface, as shown inFIG. 62.

[0490] Specific embodiments of the sixth aspect of the invention are nowdescribed.

[0491] The substrate onto which spacers are to be sprayed may have ablack matrix formed thereon, as in the fifth aspect of the invention.The same effects as mentioned above can be obtained irrespective ofwhether the black matrix is an insulating one or a conductive one.

[0492] It is preferred, however, that the black matrix is conductive,and the conductive stage comprise one or more parts each smaller in sizethan the picture frame periphery of the black matrix in each displayarea on the substrate. In such a case, the number of spacers to bedisposed in the peripheral portions of the substrate can be moresatisfactorily inhibited from decreasing.

[0493] With a color filter substrate for liquid crystal display deviceproduction which has such a constitution as mentioned hereinabove indetail referring to the fifth aspect of the invention, the effect of theearthed conductive stage is produced all over the whole region of theconductive black matrix, and the electric potential on the conductiveblack matrix lowers even when a conductive stage smaller than the regionin which the conductive black matrix is formed is used. The conductiveblack matrix region can thus reflect the effect of the conductive stage.

[0494] Therefore, even when the conductive stage is smaller than thesubstrate, an electric field suited for spacer disposition is formed inthe region in which the conductive black matrix exists.

[0495] Since, on that occasion, that region which is outside the pictureframe of the conductive black matrix is not earthed, the electricpotential of the glass portion of the substrate is influenced by thevoltage applied to the transparent electrodes, and said electricpotential rises in the direction approaching to the electric potentialof the transparent electrodes. The state in which the region outside thepicture frame of the conductive black matrix is not earthed isencountered, for example, when there is a portion of the black matrixbut the portion is separated from the picture frame by a parting line,or when there is no conductive black matrix portion outside the pictureframe of the conductive black matrix.

[0496] When, in that state, the electric potential within the displayarea is compared with that outside the display area, a higher electricpotential owing to the high voltage applied to the transparentelectrodes and a lower electric potential in each transparent electrodegap exist within the display area.

[0497] On the other hand, when a dummy electrode is formed, the dummyelectrode and the substrate glass portion both have a high electricpotential, as shown in FIG. 63. Thus, from the whole substrateviewpoint, a high electric potential region is formed outside thedisplay area and a low electric potential region is formed within thedisplay area.

[0498] Therefore, the high electric potential region outside the displayarea serves as a wall of repulsive force and thus inhibits spacerswithin the display area from escaping to the outside of the displayarea. As a result, the number of spacers within the display area becomesuniform and the cell thickness is thereby rendered uniform, with theresult that the product liquid crystal display device shows uniformdisplay characteristics.

[0499] Even in cases where the substrate onto which spacers are to besprayed is a dual-panel one having a number of display areas formedthereon, the same effects as mentioned above can be produced for alldisplay areas, if the black matrix is conductive, by providing aplurality of conductive stages each having a size such that each stagelies within the picture frame periphery of the black matrix in eachdisplay area.

[0500] In the above case, a plurality of conductive stages mayrespectively be disposed corresponding to the plurality of display areasor grooves may be formed on a single conductive stage to give aplurality of conductive stages.

[0501] The area of contact between the above conductive stage andsubstrate is preferably not less than 30% of the area of the displayarea.

[0502] In cases where a conductive black matrix is formed as mentionedabove, the conductive black matrix reflects the effect of the conductivestage even if the conductive stage is smaller than the black matrixregion. As a result, an electric field suited for spacer disposition isformed.

[0503] However, if the area of contact between the conductive stage anddisplay area (black matrix region) is too small, the effect of earthingwill become weak. Therefore, for forming an electric field suited forspacer disposition above the display area, the area of contact betweenthe conductive stage and substrate should preferably be not less than30% of the area of the display area on the substrate. When it is lessthan 30%, the effect of earthing becomes weak, the electric field suitedfor spacer disposition disintegrates and the spacer disposition in theperipheral region of the display area becomes difficult.

[0504] The particle sprayer according to the seventh aspect of theinvention is intended for selectively disposing charged particle on asubstrate having a plurality of electrodes,

[0505] said particle sprayer comprising

[0506] a nozzle for spraying charged particles onto the substrate,

[0507] a conductive stage having a fixed position and serving to holdthe substrate onto which charged particles are to be sprayed,

[0508] a plurality of push-up pins for mounting the substrate on anddismounting the substrate from the conductive stage, a probe forapplying a voltage identical in polarity with the charged particles to aplurality of electrodes on the substrate disposed on the conductivestage,

[0509] and a conductor electrically insulated from the conductive stage,said conductor being a conductive frame provided with an opening smallerin size than the substrate, disposed on the top of the substratedisposed on the conductive stage and being applied a voltage of the samepolarity as the charged particle polarity thereto.

[0510] The above transparent electrodes, substrate, particles andparticle charging method are the same as those mentioned hereinabovereferring to the first aspect of the invention.

[0511] The earthed conductive stage, the method of applying a voltage ofthe same polarity as the spacer charge polarity to the transparentelectrodes formed on the substrate, the material of the conductor, theshape and size of the conductor, the method of insulating the conductivestage from the conductor, the method of voltage application to thesubstrate, the voltage values to be applied to the transparentelectrodes on the substrate and to the conductive frame and the methodof forming the conductive frame are the same as those mentionedhereinabove referring to the fourth aspect of the invention.

[0512] The particle sprayer according to the seventh aspect of theinvention can be applied to the production of liquid crystal displaydevices and, in that case, those spacers mentioned in reference to thefirst aspect of the invention may be used as the particles.

[0513] Here, it is desirable that the probe and conductor can move upand down in synchronization with each other or integrally with eachother and/or, further, that the probe, conductor and push-up pins can bedriven in synchronization with one another by a single drivingmechanism.

[0514] It is preferred that one and the same voltage is applied to theplurality of electrodes and the conductor simultaneously.

[0515] Specific embodiments of the seventh aspect of the invention asapplied to the production of liquid crystal display devices are nowdescribed referring to FIGS. 64 to 68.

[0516]FIG. 64 shows a schematic sectional view of an example of theparticle sprayer according to the seventh aspect of the invention, FIG.65 is an explanatory view showing the manner of feeding and carrying-outof the substrate in operating the sprayer shown in FIG. 64, FIG. 66 isan enlarged explanatory view of the essential parts of the sprayer shownin FIG. 64, and FIG. 67 is an explanatory plan view showing the relationbetween the substrate and conductive frame.

[0517] As shown in FIG. 64, the particle sprayer comprises a particletank 11 b for feeding spacers, which are particles to be sprayed onto asubstrate, together with an air flow, a pipe 17 for carrying, by meansof an air flow, the spacers supplied by the particle tank 11 b tothereby cause the spacers to be charged as a result of their contactingwith the pipe inside wall on the way to the site of spraying, a chamber10 for spraying the spacers onto the substrate. The chamber 10 has, atits lower part, a driving mechanism 31 for driving a conductive frame, aprobe, push-up pins and so forth, which are to be described laterherein, in the vertical direction and, on its side, a robot mechanism 32for feeding the substrate onto which spacers are to be sprayed into thechamber 10 and taking out the substrate having spacers sprayed thereonfrom within the chamber 10.

[0518] The chamber 10 is equipped, at its top, with a nozzle 11 a forspraying the charged spacers fed through the pipe 17 from the particletank 11 b uniformly over a predetermined spacer spraying range 33 whileswinging and, at its lower part, with a conductive stage 15 for holdingthe substrate 1 for liquid crystal display device production as mountedthereon. This conductive stage 15 is disposed at a fixed positionrelative to the chamber 10, and the spacers sprayed from the nozzle 11 afall onto and are disposed on the substrate 1 held by the top surface ofthe conductive stage.

[0519] The conductive stage 15 holds the substrate 1 placed thereon and,above this substrate 1, there is disposed vertically movably aconductive frame 34 which is to be overlapped and laid on the uppersurface of the substrate 1. This conductive frame 34 is a thinplate-like conductor or a thin plate-like body coated with a conductivematerial and has a size sufficiently greater than the spacer sprayingrange 33 of the nozzle 11 a and has an opening 34 a, which is greaterthan the display area of the substrate 1 but smaller than the substrate1 for exposing the display electrode domain comprising the transparentelectrodes 3 on the substrate 1, as shown in FIG. 67.

[0520] It is preferred that this opening 34 a be greater than thedisplay area of a liquid crystal display device produced from thesubstrate 1 and other parts but be smaller than the dummy electroderegion formed outside the display electrode region comprising displayelectrodes 3 for producing an antistatic effect, among others.

[0521] Above the conductive frame 34, there is a probe 35 which ismovable up and down in synchronization with the conductive frame 34 andpresses its tip or point to a transparent electrode 3 (preferably adummy electrode) on the substrate 1 and thereby applies a voltage to thetransparent electrodes 3. This probe 35 is connected, together with theconductive frame 34, with a voltage application apparatus 12 (cf. FIG.64) and serves to apply a predetermined voltage having the same polarityas the spacer charge polarity to the transparent electrodes 3 on thesubstrate 1 and conductive frame 34.

[0522] Here, a force is preferably exerted on the probe 35 in a downwarddirection by means of a spring (not shown) so that the probe may stablycontact with a transparent electrode 3 on the substrate 1. When adownward force is exerted on it, it may be fixed to the conductive frame34, as shown in FIG. 66, or, when the same voltage is applied to theconductive frame 34 and the transparent electrodes 3 on the substrate 1,a conductor connector (not shown) may be provided as the probe 35, whichis connected with the transparent electrodes 3 on the substrate 1disposed in contact with the lower surface of the conductive frame 34.

[0523] For feeding the substrate 1 to be mounted on and held by theupper surface of the conductive stage 15 or taking out the substrate 1,a plurality of push-up pins 36 extending through the conductive stage 15are provided so that they may push up the substrate 1 and enableinsertion of arms 32 a of the robot mechanism 32, as shown in FIG. 65.

[0524] These push-up pins 36 push up the substrate 1 and enableinsertion of the arms 32 a of the robot mechanism 32 and, further, peelthe substrate 1 from the conductive stage 15 electrostatically kept inintimate contact therewith by the voltage applied in spacer spraying bythe nozzle 11 a while introducing air from the surroundings of thesubstrate. Preferably, those pins which push up the periphery of thesubstrate have a slightly greater length and those pins which push upthe middle of the substrate have a slightly shorter length so that airintroduction from around the periphery of the substrate may befacilitated.

[0525] For facilitating the peeling of the substrate 1 from theconductive stage 15, it is also possible to provide the conductive stage15 with air holes (not shown) and feed air to between the conductivestage 15 and substrate 1 therethrough. In that case, it is no morenecessary to make those push-up pins 36 on the substrate peripherylonger.

[0526] By providing such air holes, it is also possible to facilitatethe peeling of the substrate 1 by blowing air therethrough in pushing upthe substrate 1 by means of the push-up pins 36 after bring thesubstrate 1 into intimate contact with the conductive stage byevacuation therethrough in mounting and holding the substrate 1 on theupper surface of the conductive stage 15.

[0527] The push-up pins 36 and conductive frame 34 are connected withthe single driving mechanism 31. In accordance with the seventh aspectof the invention, this driving mechanism 31 is a flat plate-like onedisposed below the conductive stage 15. When this flat plate-likedriving mechanism 31 is moved up and down by means of a driving source(not shown), the push-up pins 36 and conductive stage 34 move up anddown accordingly.

[0528] In feeding the substrate 1 or taking out the same, it isnecessary to first raise the conductive frame 34 to make it possible toraise the push-up pins 36 and then raise the push-up pins 36 to therebypeel and lift the substrate 1 off from the conductive stage 15.

[0529] For this purpose, according to the seventh aspect of theinvention, measures are taken so that a gap A may be formed between thesubstrate 1 and push-up pins 36 when the driving mechanism 31 is in itsdescended state, as shown in FIG. 66. Thus, when the driving mechanism31 is raised, the conductive frame 34 alone is raised in the beginningand, after the rise of the conductive frame 34 by the gap A, the push-uppins rise to contact with the substrate 1 and then peel off the samefrom the conductive stage 15 and lift the same.

[0530] By separating, in the above manner, the substrate 1 from theconductive frame 34 by the gap A in the raised state of the drivingmechanism 31, a sufficient gap is secured to slightly raise the arms 32a so that the substrate 1 may be out of contact with the push-up pins 36in the step of feeding or taking out the substrate 1 by means of therobot mechanism 32.

[0531] A typical example of the layout of the push-up pins 36, thepush-up shafts 34 b of the conductive frame 34 and the arms 32 a of therobot mechanism 32 is shown in FIG. 67. As shown in FIG. 67, a number ofpush-up pins 36 are preferably provided so that the substrate 1 may notbe damaged in the step of peeling the substrate 1 off from theconductive stage 15.

[0532] The push-up shafts 34 b of the conductive frame 34 are desirablydisposed around the substrate 1 or conductive stage 15 so that they maynot interfere with the latter. The arms 32 a of the robot mechanism 32are drawn by imaginary lines on the left of FIG. 67. The arms 32 aformed as a plurality of branches so that they may not interfere withthe push-up pins 36 or with the push-up shafts 34 b of the conductiveframe 34 are provided with sucking cups 32 b for sucking and holding thesubstrate 1.

[0533]FIG. 68 is an explanatory view showing an equipotential line 37observed when a voltage is applied to the conductive frame 34 and thetransparent electrodes 3 on the substrate 1. As shown in FIG. 68, theelectric potential is higher above the conductive frame 34 andtransparent electrodes 3 and it is lower in each gap between electrodes(interelectrode gap), namely in each gap between neighboring transparentelectrodes and in each gap between the conductive frame 34 and theneighboring transparent electrode 3.

[0534] Since the spacers sprayed from the nozzle 11 a are charged andhave the same polarity as the polarity of the voltage applied to theconductive frame 34 and transparent electrode domain 3, the spacers fallwhile being repelled by the repulsive force exerted by the electricfield above the substrate, move toward the positions where the electricpotential is low, and drop concentratedly in interelectrode gaps, namelythe gaps between respective transparent electrodes and gaps between theconductive frame 34 and the respective neighboring transparentelectrodes 3.

[0535] In the region outside the conductive frame 34, which are far awayfrom the spacer spraying range 33, no spacer drops outside theconductive frame 34 even if there is repulsion by a repulsive force. Thespacers sprayed from the nozzle 11 a thus fall only onto the transparentelectrode gaps and the gaps between the conductive frame 34 and therespective neighboring transparent electrodes 3.

[0536] The voltages to be applied to the conductive frame 34 andtransparent electrodes 3 can be selected so that spacers fall onto thetransparent electrode gaps and the gaps between the conductive frame 34and the respective neighboring transparent electrodes 3 with anappropriate probability. By selecting one and the same voltage andselecting the gap distance between the neighboring transparentelectrodes 3 and between the conductive frame 34 and the neighboringtransparent electrodes 3 so that spacers may fall therein with anappropriate probability, it is possible, in gradually applying thevoltage to or removing the same from the transparent electrodes 3 on thesubstrate 1 and the conductive frame 34, to simultaneously apply thevoltage to them or remove the same therefrom and thus facilitate thevoltage control on. the power source apparatus 12.

[0537] Some typical embodiments of the seventh aspect of the inventionhave been described above. It is to be noted, however, that the seventhaspect of the invention is not limited to these embodiments but variousmodifications and variations can of course be made without departingfrom the spirit of the seventh aspect of the invention.

[0538] The eighth aspect of the invention is related to the liquidcrystal display device produced by using the method of sprayingparticles according to the first aspect of the invention.

[0539] The ninth aspect of the invention is related to the liquidcrystal display device produced by the method for producing a liquidcrystal display device according to the second or third aspect of theinvention.

[0540] The tenth aspect of the invention is related to the liquidcrystal display device produced by the method for producing. a liquidcrystal display device according to the fourth, fifth or sixth aspect ofthe invention while using the particle sprayer according to the seventhaspect of the invention.

[0541] The liquid crystal display device according to the eighth, ninthor tenth aspect of the invention is uniform in cell thickness and showhigh quality display characteristics without display unevenness.

BEST MODES FOR CARRYING OUT THE INVENTION

[0542] The following examples illustrate the present invention infurther detail. They are, however, by no means limitative of the scopeof the invention.

EXAMPLE 1

[0543] A pair of soda glass-made insulating substrates each having anouter size of 370×480 mm and a thickness of 0.7 mm were used. On one ofthe insulating substrates 1, there were formed RGB color filters 4 witha black matrix 5, which is a light shielding layer, and an overcoat 6for protecting the color filters 4. On the overcoat 6 were formedstripe-shaped display electrodes 3 made of ITO and further an alignmentlayer 9 made of a polyimide resin. After alignment treatment, a sealingmaterial 24 was applied by the technique of screen printing. Glass beadsto serve as spacers 25 within the sealing material was incorporated inthe sealing material 24.

[0544] On the other insulating substrate 1, there were formed, as shownin FIG. 5 and FIG. 69, 285-μm-wide stripe-shaped display electrodes 3made of ITO and having a thickness of 300 nm at intervals of 15 μm.Auxiliary electrodes 20 were further formed for voltage application tothe display electrodes 3, dummy electrodes 21 were formed along thesides where there was no auxiliary electrode 20 and, further, aninsulating layer 23 and an alignment layer 9 made of a polyimide resinwere formed. In some instances, the insulating layer 23 need not beformed.

[0545] Here, the dummy electrodes 21 were electrically connectedtogether by means of a conductive material (effective in reducing thenumber of power supplying parts). In FIG. 69, dummy electrodes 21 aredisposed only along the upper, lower and right sides of the effectivedisplay area. This is because there are the auxiliary electrodes 20 forvoltage application to the display electrodes outside the left side ofthe effective display area and this produces the same effect as thedummy electrodes 21 produces.

[0546] Using synthetic resin particles, BBS-60510-PH (product of SekisuiFine Chemical), as spacers, these were charged negatively and sprayedonto said other insulating substrate 1. On that occasion, a voltage of−2 kV was applied to the display electrodes 3 and to the dummyelectrodes 21 (cf. FIG. 5).

[0547] As a result, spacers 8 could be disposed only in the gaps betweendisplay electrodes 3. The selectivity of disposition of spacers 8 ininterelectrode gaps was improved as compared with the case in which nodummy electrode 21 was provided.

[0548] Then, the insulating substrates 1 forming a pair were lapped overeach other, hot-pressed at 180° C. and 0.8 kg/cm² and post-baked at 150°C. Thereafter, trimming was performed for removing unnecessary portions,whereupon the auxiliary electrodes 20 and dummy electrodes 21 were cutoff. Then, a liquid crystal 7 was poured therebetween to give a liquidcrystal display device (shown in FIG. 70) in which the pair ofinsulating substrates were bonded together.

EXAMPLE 2

[0549] A pair of soda glass-made insulating substrates each having anouter size of 370×480 mm and a thickness of 0.7 mm were used. On one ofthe insulating substrates 1, there were formed RGB color filters 4 witha black matrix 5, which is a light shielding layer, and an overcoat 6for protecting the color filters 4. On the overcoat 6 were formedstripe-shaped display electrodes 3 made of ITO and further an alignmentlayer 9 made of a polyimide resin. After alignment treatment, a sealingmaterial 24 was applied by the technique of screen printing. Glass beadsto serve as spacers 25 within the sealing material was incorporated inthe sealing material 24.

[0550] On the other insulating substrate 1, there were formed, as shownin FIG. 11 and FIGS. 13-16, 285-μm-wide stripe-shaped display electrodes3 a and 3 b made of ITO and having a thickness of 300 nm at intervals of15 μm. Auxiliary electrodes 20 a and 20 b and accessory electrodes 29were formed and, further, an insulating layer 23 and an alignment layer9 made of a polyimide resin were formed. The insulating layer 23 neednot be formed in some instances.

[0551] Using synthetic resin particles, BBS-60510-PH (product of SekisuiFine Chemical), as spacers, these were charged negatively and sprayedonto said other insulating substrate 1. On that occasion, a voltage of−500 V was applied to the display electrodes 3 a and −700 V to thedisplay electrodes 3 b, to produce a potential difference of 200 Vbetween the display electrodes 3 a and 3 b. The same voltage as thatapplied to the display electrodes 3 b, namely −700 V, was applied to theaccessory electrodes 29 (cf. FIG. 11 and FIGS. 13-16).

[0552] As a result, spacers 8 could be disposed only in the gaps betweendisplay electrodes 3 a and the density of spacers disposed in the gapsbetween display electrodes 3 a, inclusive of those gaps between displayelectrodes 3 a in the vicinity of the periphery of each display area 30,could be rendered uniform within the display area 30.

[0553] Furthermore, spacers 8 could be disposed concentratedly in themiddle of each gap between display electrodes 3 a and the probability ofspacers 8 being disposed in the edge portions of the display electrodes3 a could be reduced.

[0554] Then, the insulating substrates 1 forming a pair were lapped overeach other, hot-pressed at 180° C. and 0.8 kg/cm² and post-baked at 150°C. Thereafter, trimming was performed for removing unnecessary portions,whereupon the auxiliary electrodes 20 a and 20 b and accessoryelectrodes 29 were cut off. Then, a liquid crystal 7 was pouredtherebetween to give a liquid crystal display device (shown in FIG. 70)in which the pair of insulating substrates were bonded together.

EXAMPLE 3

[0555] Spacers 8 were sprayed in the same manner as in Example 2 exceptthat +500 V was applied to the display electrodes 3 a and +300 V to thedisplay electrodes 3 b on the other insulating substrate 1, to give apotential difference of 200 V between the display electrodes 3 a and 3 bwhile the same voltage as applied to the display electrodes 3 a (+500 V)was applied to the accessory electrodes 29 (cf. FIG. 11 and FIGS.17-20).

[0556] As a result, spacers 8 could be disposed only in the gaps betweendisplay electrodes 3 a, and the density of spacers disposed in the gapsbetween display electrodes 3 a, inclusive of those gaps between displayelectrodes 3 a in the vicinity of the periphery of each display area 30,could be rendered uniform within the display area 30.

[0557] Thereafter, a liquid crystal display device was manufactured inthe same manner as in Example 2.

EXAMPLE 4

[0558] Spacers 8 were sprayed in the same manner as in Example 2 exceptthat +50 V was applied to the display electrodes 3 a and −150 V to thedisplay electrodes 3 b on the other insulating substrate 1, to give apotential difference of 200 V between the display electrodes 3 a and 3 bwhile −100 V was applied to the accessory electrodes 29 by connecting aconductor wire 18 therewith (cf. FIG. 12, FIG. 17 and FIGS. 21-23).

[0559] As a result, spacers 8 could be disposed only in the gaps betweendisplay electrodes 3 a and the density of spacers disposed in the gapsbetween display electrodes 3 a, inclusive of those gaps between displayelectrodes 3 a in the vicinity of the periphery of each display area 30,could be rendered uniform within the display area 30.

[0560] Thereafter, a liquid crystal display device was manufactured inthe same manner as in Example 2.

EXAMPLE 5

[0561] Spacers 8 were sprayed in the same manner as in Example 2 exceptthat +150 V was applied to the display electrodes 3 a and −50 V to thedisplay electrodes 3 b on the other insulating substrate 1, to give apotential difference of 200 V between the display electrodes 3 a and 3 bwhile +100 V was applied to the accessory electrodes 29 by connecting aconductor wire 18 therewith (cf. FIG. 12, FIG. 17 and FIGS. 24-26).

[0562] As a result, spacers 8 could be disposed only in the gaps betweendisplay electrodes 3 a and the density of spacers disposed in the gapsbetween display electrodes 3 a, inclusive of those gaps between displayelectrodes 3 a in the vicinity of the periphery of each display area 30,could be rendered uniform within the display area 30.

[0563] Thereafter, a liquid crystal display device was manufactured inthe same manner as in Example 2.

EXAMPLE 6

[0564] Spacers 8 were sprayed in the same manner as in Example 2 exceptthat +50 V was applied to the display electrodes 3 a and −150 V to thedisplay electrodes 3 b on the other insulating substrate 1, to give apotential difference of 200 V between the display electrodes 3 a and 3 bwhile −100 V was applied to the accessory electrodes 29 by connecting aconductor wire 18 therewith (cf. FIGS. 27-31).

[0565] As a result, spacers 8 could be disposed only in the gaps betweendisplay electrodes 3 a and the density of spacers disposed in the gapsbetween display electrodes 3 a, inclusive of those gaps between displayelectrodes 3 a in the vicinity of the periphery of each display area 30,could be rendered uniform within the display area 30.

[0566] Thereafter, a liquid crystal display device was manufactured inthe same manner as in Example 2.

EXAMPLE 7

[0567] Spacers 8 were sprayed in the same manner as in Example 2 exceptthat −300 V was applied to the display electrodes 3 a and accessoryelectrodes 29 a and −500 V to the display electrodes 3 b and accessoryelectrodes 29 b on the other insulating substrate 1, to give a potentialdifference of 200 V between the display electrodes 3 a and 3 b (cf.FIGS. 32-35).

[0568] As a result, spacers 8 could be disposed only in the gaps betweendisplay electrodes 3 a and the density of spacers disposed in the gapsbetween display electrodes 3 a, inclusive of those gaps between displayelectrodes 3 a in the vicinity of the periphery of each display area 30,could be rendered uniform within the display area 30.

[0569] Thereafter, a liquid crystal display device was manufactured inthe same manner as in Example 2.

EXAMPLE 8

[0570] Spacers 8 were sprayed in the same manner as in Example 2 exceptthat +300 V was applied to the display electrodes 3 a and +500 V to thedisplay electrodes 3 b on the other insulating substrate 1, to give apotential difference of 200 V between the display electrodes 3 a and 3 bwhile the same voltage as applied to the display electrodes 3 b (+500 V)was applied to the accessory electrodes 29 (cf. FIG. 11, FIG. 17 andFIGS. 36-38).

[0571] As a result, spacers 8 could be disposed only in the gaps betweendisplay electrodes 3 a and the density of spacers disposed in the gapsbetween display electrodes 3 a, inclusive of those gaps between displayelectrodes 3 a in the vicinity of the periphery of each display area 30,could be rendered uniform within the display area 30.

[0572] Furthermore, spacers 8 could be disposed concentratedly in themiddle of each gap between display electrodes 3 a and the probability ofspacers 8 being disposed in the edge portions of the display electrodes3 a could be reduced.

[0573] Thereafter, a liquid crystal display device was manufactured inthe same manner as in Example 2.

EXAMPLE 9

[0574] A common electrode substrate (substrate having a sheet thicknessof 0.7 mm with color filters formed thereon; aperture of each of RGBpixels=80×285 μm, black matrix line width=20 μm, ITO electrode width=290μm, electrode gap distance=15 μm) for STN type liquid crystal displaydevice production, as shown in FIG. 45, was prepared (after spacerdisposition and the subsequent cutting off of the conductor lines,giving a common electrode substrate like the conventional one).

[0575] A 0.05-μm-thick polyimide alignment layer was formed on thissubstrate and subjected to rubbing treatment.

[0576] A spacer sprayer, such as shown in FIG. 71, was used as thesprayer. An antistatic mat having a surface resistance of not more than10⁷ Ωcm was laid in intimate contact with an earthed conductive stagemade of aluminum and disposed in the lower part of the sprayer body, andthe substrate was disposed thereon in close contact with the mat. Twoconnecting terminals for voltage application connected with a voltageapplication apparatus were provided within the sprayer and wires wereintroduced into the sprayer so that different direct current voltagesmight be applied to the transparent electrodes formed on the substrate.

[0577] Micropearl BB-6.8 μm-PH (trademark; product of Sekisui FineChemical) particles were prepared as spacers.

[0578] Then, the terminals for voltage application were connected with apower source and a voltage of −2.7 kV was applied to each dualconducting part (conducting line (A)) of 2:1 type comb-shaped electrodesand a voltage of −2.8 kV to each other conducting part (conducting line(B)).

[0579] Then, the conducting part (conducting line (A)) to which thevoltage of −2.7 kV was applied was connected with each dummy electrodeby wiring so that all dummy electrodes might have the same electricpotential (in FIG. 45, the conducting line (A) was further connectedwith the dummy electrodes by wiring).

[0580] While maintaining this state, the spacers were passed through astainless steel pipe capable of charging them negatively (−) and sprayedonto the substrate by means of compressed air. That the spacers werenegatively charged on that occasion had been confirmed beforehand.

[0581] Observation of the substrate with the spacers sprayed thereonunder the light microscope revealed that the spacers were disposed atblack matrix sites in each gap between the two neighboring electrodesinvolved therein to which the voltage of −2.7 kV had been applied,uniformly all over the substrate.

Comparative, Example 1

[0582] The procedure of Example 9 was followed in the same manner exceptthat no voltage was applied to the dummy electrodes.

[0583] Observation of the substrate with the spacers sprayed thereonunder the light microscope revealed that the spacers were disposed atblack matrix sites in each gap between the two neighboring electrodesinvolved therein to which the voltage of −2.7 kV had been applied butthat there were marked decreases in the number of spacers in theperipheral region from the periphery of each display area to a lineabout 10 mm inside said periphery.

EXAMPLE 10

[0584] The procedure of Example 9 was followed in the same manner exceptthat the substrate used had 2:1 type comb-shaped electrodes each singleconducting part (conducting line (B)) of which was connected with thedummy electrodes, as shown in FIG. 44, and that a voltage of −2.7 kV wasapplied to each dual conducting part (conducting line (A)) of the 2:1type comb-shaped electrodes, and a voltage of −2.8 kV to each otherconducting part (conductor line (B)).

[0585] Observation of the substrate with the spacers sprayed thereonunder the light microscope revealed that the spacers were disposed atblack matrix sites in each gap between the two neighboring electrodesinvolved therein to which the voltage of −2.7 kV had been applied,uniformly all over the substrate.

EXAMPLE 11

[0586] The procedure of Example 9 was followed in the same manner exceptthat the dummy electrodes were connected respectively and a voltage of−2.75 kV was applied thereto using a separate voltage applicationapparatus.

[0587] Observation of the substrate with the spacers sprayed thereonunder the light-microscope revealed that the spacers were disposed atblack matrix sites in each gap between the two neighboring electrodesinvolved therein to which the voltage of −2.7 kV had been applied,uniformly all over the substrate.

EXAMPLE 12

[0588] A common electrode substrate (substrate having a glass thicknessof 0.7 mm with color filters formed thereon; aperture of each of RGBpixels=80×285 μm, metallic chromium-made black matrix line width=35 μm,acrylic resin overcoat layer=3.0 μm, ITO electrode width=290 μm,electrode gap distance=25 μm) for STN type liquid crystal display deviceproduction was prepared as the substrate.

[0589] A 0.05-μm-thick polyimide alignment layer was formed on thissubstrate and subjected to rubbing treatment.

[0590] The ITO electrodes were formed as shown in FIG. 3.

[0591] A spacer sprayer, such as shown in FIG. 71, manufactured byNisshin Engineering was used as the sprayer. Prepared as the spacerswere Micropearl BB, 7.25 μm-PH (trademark; product of Sekisui FineChemical) particles.

[0592] An earthed aluminum stage and an aluminum conductive frame weredisposed within the sprayer, as shown in FIG. 46. The stage wasinsulated from the conductive frame by a butyl rubber type resin, andmeasures were taken so that voltage application might be made to boththe ITO display electrodes and dummy electrodes, as shown in FIG. 50.Each probe used had a size sufficient to exert a pressure on severalelectrodes.

[0593] By applying −2.0 kV to the conductive frame by means of a voltageapplication apparatus, the same voltage of −2.0 kV was applied to thedummy electrodes and ITO display electrodes.

[0594] While maintaining the above state, the spacers were sprayed ontothe substrate. The spacers were negatively (−) charged upon spraying.

[0595] Observation of the substrate with the spacers sprayed thereonunder the light microscope revealed that the spacers were disposed inelectrode gaps (black matrix sites) and, even in the peripheral displayarea, they were disposed uniformly.

EXAMPLE 13

[0596] The spacers were sprayed in the same manner as in Example 12except that a substrate having such a structure as shown in FIG. 2 inwhich the dummy electrode and display electrodes were connected togetherwas used in lieu of the substrate used in Example 12, that theconstitution of the stage and conductive frame was as shown in FIG. 46and that the voltage application from the conductive frame to the dummyelectrode was carried out in the manner shown in FIG. 49.

[0597] Observation of the substrate with the spacers sprayed thereonunder the light microscope revealed that the spacers were disposed inelectrode gaps (black matrix sites) and, even in the peripheral displayarea, they were disposed uniformly.

EXAMPLE 14

[0598] The stage and conductive frame were constituted as shown in FIG.47, a substrate having such an electrode structure as shown in FIG. 2was used, a terminal derived from a voltage application apparatus wasconnected with the dummy electrode, and −2.0 kV was applied to the ITOdisplay electrodes and dummy electrode.

[0599] Separately, a voltage of −2.7 kV was applied to the conductiveframe using another power source. While maintaining this state, thespacers were sprayed as mentioned in Example 12.

[0600] Observation of the substrate with the spacers sprayed thereonunder the light microscope revealed that the spacers were disposed inelectrode gaps (black matrix sites) and, even in the peripheral displayarea, they were disposed uniformly.

Comparative Example 2

[0601] In Example 12, no conductive frame was used and the substrate wasdisposed directly on the stage so that voltage application might be madeonly to the ITO display electrodes by means of rod-shaped electrodes.Thus, −2.0 kV was applied thereto. In that state, the spacers weresprayed in the same manner as in Example 12.

[0602] Observation of the substrate with the spacers sprayed thereonunder the light microscope revealed that the spacers were disposed inelectrode gaps in the middle region of the substrate but no spacers werefound in the peripheral zone (about 30 mm wide) of the display area.

EXAMPLE 15

[0603] A common electrode substrate (substrate having a glass thicknessof 0.7 mm with color filters formed thereon; aperture of each of RGBpixels=80×285 μm, metallic chromium-made black matrix line width=35 μm,acrylic resin overcoat layer=3.0 μm, ITO electrode width=290 μm,electrode gap distance=25 μm) for STN type liquid crystal display deviceproduction was prepared as the substrate.

[0604] A 0.05-μm-thick polyimide alignment layer was formed on thissubstrate and subjected to rubbing treatment.

[0605] The ITO electrodes were formed as shown in FIG. 2 and measureswere taken, as shown in FIG. 72, so that a voltage might be applied toall ITO electrodes on the substrate by applying the voltage to the dummyelectrode.

[0606] A Nisshin Engineering model DISPA-μR (trademark) sprayer was usedas the sprayer and, as shown in FIG. 73, chromium foil sections wereprovided on a flat vinyl chloride resin plate within the sprayer, themiddle section, which was serve as the conductive stage, was earthed, aconductive frame was formed around the same and a terminal derived froma voltage application apparatus was connected with a part thereof sothat voltage supply might be made via that terminal.

[0607] The positional relations among the substrate, stage andconductive frame were as shown in FIG. 57. Thus, the conductive stagewas smaller in size than the substrate but was large enough to reach theinside of the dummy electrode domain (region outside the trimminglines), the conductive frame was formed from within the dummy electrodedomain to the outside of the substrate, and the area occupied by theconductive stage and that occupied by the conductive frame within thedummy electrode domain were as follows: [area of conductive stage]>[areaof conductive frame]. Further, a state was produced in which thesubstrate end portion,underside was in contact with the conductiveframe.

[0608] Prepared as the spacers were Sekisui Fine Chemical's MicropearlBB-PH (trademark), 7.25 μm in particle size.

[0609] Then, −2.0 kV was applied to the dummy electrode and ITOelectrodes by applying −2.0 kV to the conductive frame by means of avoltage application apparatus and, while maintaining this state, thespacers were sprayed onto the substrate. The negative charging of thespacers had been confirmed beforehand.

[0610] Observation of the substrate with the spacers sprayed thereonunder the light microscope revealed that the spacers were disposed inelectrode gaps, namely at black matrix sites. Furthermore, the spacerswere uniformly disposed in the peripheral area of the display area aswell.

[0611] Thereafter, this substrate was used to complete a liquid crystaldisplay device in the conventional manner. The thus-completed liquidcrystal display device showed high contrast owing to the absence ofspacers at pixel sites, and showed good display performancecharacteristics with good display evenness owing to the spacerdisposition all over the substrate, unlike the cases of spacer sprayingby the conventional methods of liquid crystal display device production.

EXAMPLE 16

[0612] The procedure of Example 15 was followed in the same mannerexcept that the conductive stage and conductive frame were made ofseparate stainless steel plates. The conductive frame was fixed withinthe sprayer by means of Teflon-made supporting rods, and the conductivestage and the conductive frame were insulated from each other by air.

[0613] Observation of the substrate with the spacers sprayed thereonunder the light microscope revealed that the spacers were disposed inelectrode gaps, namely at black matrix sites. Furthermore, the spacerswere uniformly disposed in the peripheral area of the display area aswell.

[0614] Thereafter, this substrate was used to complete a liquid crystaldisplay device in the conventional manner. The thus-completed liquidcrystal display device showed high contrast owing to the absence ofspacers at pixel sites, and showed good display performancecharacteristics with good display evenness owing to the spacerdisposition all over the substrate, unlike the cases of spacer sprayingby the conventional methods of liquid crystal display device production.

EXAMPLE 17

[0615] The procedure of Example 15 was followed in the same mannerexcept that the positional relations among the substrate, stage andconductive frame were as shown in FIG. 58. Thus, the conductive stagewas smaller in size than the substrate but sufficiently enough to reachthe inside of the dummy electrode domain (region outside the trimminglines), the conductive frame was formed outside the dummy electrodewithout overlapping with the same and, further, a state was produced inwhich the substrate end portion underside was in contact with theconductive frame.

[0616] Observation of the substrate with the spacers sprayed thereonunder the light microscope revealed that the spacers were disposed inelectrode gaps, namely at black matrix sites. Furthermore, the spacerswere uniformly disposed in the peripheral area of the display area aswell.

[0617] Thereafter, this substrate was used to complete a liquid crystaldisplay device in the conventional manner. The thus-completed liquidcrystal display device showed high contrast owing to the absence ofspacers at pixel sites, and showed good display performancecharacteristics with good display evenness owing to the spacerdisposition all over the substrate, unlike the cases of spacer sprayingby the conventional methods of liquid crystal display device production.

EXAMPLE 18

[0618] The procedure of Example 15 was followed in the same mannerexcept that the black matrix formed on the substrate was made of a resinand that the positional relations among the substrate, stage andconductive frame were as shown in FIG. 60. Thus, the size of theconductive stage was substantially identical with the domain in whichthe transparent electrodes were present, the conductive frame was formedfrom a region where there was no transparent electrode and, further, thesubstrate end portion underside was in contact with the conductiveframe.

[0619] Observation of the substrate with the spacers sprayed thereonunder the light microscope revealed that the spacers were disposed inelectrode gaps, namely at black matrix sites. Furthermore, the spacerswere uniformly disposed in the peripheral area of the display area aswell.

[0620] Thereafter, this substrate was used to complete a liquid crystaldisplay device in the conventional manner. The thus-completed liquidcrystal display device showed high contrast owing to the absence ofspacers at pixel sites, and showed good display performancecharacteristics with good display evenness owing to the spacerdisposition all over the substrate, unlike the cases of spacer sprayingby the conventional methods of liquid crystal display device production.

Comparative Example 3

[0621] The procedure of Example 16 was followed in the same mannerexcept that the conductive stage was made of stainless steel but thesize thereof remained the same and that the conductive frame was removedto give a conductive frame-free state.

[0622] Observation of the substrate with the spacers sprayed thereonunder the light microscope revealed that the spacers were disposed inelectrode gaps in the middle region of the substrate but no spacers werefound in the peripheral zone (about 30 mm wide) of the display area.

[0623] Thereafter, this substrate was used to complete a liquid crystaldisplay device in the conventional manner. The thus-completed liquidcrystal display device showed high contrast display characteristics inthe central portion of the substrate but showed display unevenness owingto the fact that the cell thickness had been reduced in the peripheralregion of the substrate.

EXAMPLE 19

[0624] The procedure of Example 15 was followed in the same mannerexcept that the conductive frame was disposed over an area extending tothe display area inside, that the substrate end portion underside was incontact with the conductive frame and that the conductive stage wassmaller than the conductive frame.

[0625] Observation of the substrate with the spacers sprayed thereonunder the light microscope revealed that the spacers were disposed inelectrode gaps in small numbers and disposed also on pixels in largenumbers.

[0626] Thereafter, this substrate was used to complete a liquid crystaldisplay device in the conventional manner. The thus-completed liquidcrystal display device was inferior in contrast to that obtained inExample 15.

EXAMPLE 20

[0627] A common electrode substrate (substrate having a glass thicknessof 0.7 mm with color filters formed thereon; aperture of each of RGBpixels=80×280 μm, resin-made black matrix line width=35 μm, acrylicresin overcoat layer=3.0 μm, ITO electrode width=290 μm, electrode gapdistance=25 μm) for STN type liquid crystal display device productionwas prepared as the substrate.

[0628] A 0.05-μm-thick polyimide alignment layer was formed on thissubstrate and subjected to rubbing treatment.

[0629] The substrate used was a dual panel substrate having two displayareas formed on one substrate.

[0630] The ITO electrodes were formed to leave a margin of about 10 mmfrom each edge of the substrate and in a manner such that voltageapplication to the dummy electrode might result in voltage applicationto all ITO electrodes on the substrate, as shown in FIG. 2.

[0631] A Nisshin Engineering model DISPA-μR (trademark) sprayer, asshown in FIG. 74, was used as the sprayer and, as shown in FIG. 62, theconductive stage was almost identical in size with the ITO electrodedomain on the substrate, hence the periphery thereof was about 10 mminside from each substrate edge.

[0632] Sekisui Fine Chemical's Micropearl BB-PH (trademark) particles,7.25 μm in particle size, were prepared as the spacers.

[0633] Then, a direct current source-derived terminal was connected withthe dummy electrode on the substrate and −2.0 kV was applied to all ITOelectrodes on the substrate and, while maintaining this state, thespacers were sprayed onto the substrate. The negative charging of thespacers had been confirmed beforehand.

[0634] Observation of the substrate with the spacers sprayed thereonunder the light microscope revealed that the spacers were disposed inelectrode gaps, namely at black matrix sites.

[0635] Thereafter, this substrate was used to complete a liquid crystaldisplay device in the conventional manner. The thus-completed liquidcrystal display device showed high contrast owing to the absence ofspacers at pixel sites, and showed good display performancecharacteristics with good display evenness owing to the spacerdisposition all over the substrate, unlike the cases of spacer sprayingby the conventional methods of liquid crystal display device production.

EXAMPLE 21

[0636] The procedure of Example 20 was followed in the same mannerexcept that a chromium black matrix with a line width of 35 μm was usedas the black matrix, and that the conductive stage used had been dividedinto two parts corresponding to the two display areas on the substrate,respectively, with the periphery of each part being 5 mm inside theblack matrix picture frame.

[0637] Observation of the substrate with the spacers sprayed thereonunder the light microscope revealed that the spacers were disposed inelectrode gaps, namely at black matrix sites.

[0638] Thereafter, this substrate was used to complete a liquid crystaldisplay device in the conventional manner. The thus-completed liquidcrystal display device showed high contrast owing to the absence ofspacers at pixel sites, and showed good display performancecharacteristics with good display evenness owing to the spacerdisposition all over the substrate, unlike the cases of spacer sprayingby the conventional methods of liquid crystal display device production.

Comparative Example 4

[0639] Spacer spraying was carried out in the same manner as in Example20 except that the conductive stage used had a size greater by 50 mmthan the substrate.

[0640] Observation of the substrate with the spacers sprayed thereonunder the light microscope revealed that the spacers were disposed inelectrode gaps, namely at black matrix sites, but few spacers were foundin the peripheral zone (about 30 mm wide) of the display area.

[0641] Thereafter, this substrate was used to complete a liquid crystaldisplay device in the conventional manner. The thus-completed liquidcrystal display device showed high contrast and good displaycharacteristics in the central portion of the display area but, in theperipheral region of the display area showed display unevenness becauseof a reduced cell thickness owing to the absence of spacers.

EXAMPLE 22

[0642] Spacer spraying was carried out in the same manner as in Example21 except that the conductive stage used had a size of 40%, 30% or 20%of the display area.

[0643] After observation of the substrates with the spacers sprayedthereon under the light microscope, these substrates were used tocomplete liquid crystal display devices in the conventional manner.

[0644] When the conductive stage having a size of 40% of the displayarea was used, the spacers were disposed in electrode gaps, namely atblack matrix sites, like in Example 21, and the liquid crystal displaydevice completed showed high contrast owing to the absence of spacers atpixel sites and had good display performance characteristics withdisplay evenness owing to the spacer disposition all over the displayarea.

[0645] When the conductive stage having a size of 30% of the displayarea was used, some spacers were disposed in pixel sites but the liquidcrystal display device completed showed little influence on the contrastand showed high contrast since the number of spacers disposed in thepixel sites was small.

[0646] When the conductive stage having a size of 20% of the displayarea was used, the spacers were disposed almost randomly on the displayarea and the liquid crystal display device completed showed noimprovement in contrast.

EXAMPLE 23

[0647] Using a particle sprayer as shown in FIGS. 64-67, a substrate 1onto which spacers were to be sprayed was first fed onto the conductivestage 15. For feeding the substrate 1, the substrate 1 was taken out ofa substrate stock site (not shown) by means of arms 32 a of a robotmechanism 32 and, at the same time, a drive mechanism 31 ascended andraised the push-up pins 36 and conductive frame 34 for producing a gapfor insertion of the substrate 1 between the push-up pins 36 andconductive frame 34.

[0648] Then, the lid 10 a of an opening provided at a chamber 10 sitefacing the robot mechanism 32 was opened and the arms 32 a of the robotmechanism 32 were inserted into the chamber and further advanced toinsert the substrate 1 between the push-up pins 36 and conductive frame34. Thereafter, the push-up pins 36 and conductive frame 34 descended,whereby the substrate 1 was fed onto and disposed on the conductivestage 15. The conductive frame 34 further descended and was disposed andheld on the conductive stage 15.

[0649] On that occasion, the probe 35 also descended with the conductiveframe 34 and the tip of the probe 35 contacted with the transparentelectrodes 3 on the substrate 1 and thus the preparation for voltageapplication to the conductive frame 34 and to the transparent electrodes3 on the substrate 1 was completed. Then, a voltage of +1 kV wasgradually applied to the conductive frame 34 and to the transparentelectrodes 3 on the substrate 1. (Sudden application of a high voltageis undesirable since such a trouble as dielectric breakdown of thetransparent electrodes 3 may be caused.)

[0650] Since, on that occasion, the conductive stage 15 was earthed, asshown in FIG. 64, and the substrate 1 was formed from an insulatingmaterial, the substrate 1 was attracted by and fixed on the conductivestage 15 by the static electricity generated between the substrate 1 andconductive stage 15. If necessary, the substrate 1 may be positioned ona predetermined location on the conductive stage 15 by using positioningpins or the like.

[0651] And, spacers were charged positively and sprayed from the nozzle11 a. As a result, as shown in FIG. 68, the spacers were sprayedconcentratedly into the gaps between transparent electrodes 3 and thegaps between the conductive frame 34 and transparent electrodes 3.

[0652] The voltage being applied to the substrate 1 with the spacersdisposed thereon in the above manner only in the electrode gaps and thegaps between the conductive frame 34 and electrodes 3 was graduallylowered again, and the substrate 1 was taken out to a finished goodsstock site by the robot mechanism 32 (this time, the procedure offeeding the substrate 1 was reversed).

INDUSTRIAL APPLICABILITY

[0653] The method of spraying particles according to the presentinvention, which is constituted as mentioned above, makes it possible todispose a predetermined quantity of particles in desired positions, todispose spacers in electrode gaps in liquid crystal display deviceswithout sacrificing the aperture ratio and, further, to properly disposespacers in electrode gaps in the peripheral region of the display areaas well by applying a voltage to an electrode or electrodes outside thedisplay area.

[0654] The method of liquid crystal display production according to theinvention, which is constituted as mentioned above, makes it possible,in conducting the method for producing a liquid crystal display devicecomprising disposing charged spacers in electrode gaps while applying avoltage to the transparent electrodes, to dispose spacers selectivelyonly in predetermined transparent electrode gaps among neighboringtransparent electrode gaps, namely at black matrix sites, even in thecase of stripe-shaped transparent electrodes such as employed in STNtype liquid crystal display devices, and to control the spacerdisposition density in the vicinity of the peripheral portions of thedisplay area as well as in the middle part of the display area, wherebyit becomes possible to make the spacer disposition density uniformwithin the display area and thus provide liquid crystal display devicesimproved in contrast while preventing light leakage through spacers,without sacrificing the aperture ratio.

[0655] Further, since spacers can be disposed all over the substrate,the liquid crystal display device produced therefrom can have a uniformcell thickness and high quality display performance characteristicswithout display unevenness. Furthermore, spacers can be sprayed atpredetermined sites other than electrode sites without the need ofproviding, outside the display area, a dummy electrode or electrodessufficiently larger than the area of spacer spraying.

[0656] Furthermore, the liquid crystal display device according to theinvention, which is constituted as mentioned above, has a uniform cellthickness and high quality display performance characteristics withoutdisplay unevenness.

1. A method of spraying particles which comprises applying a voltage ofthe same polarity as the particle charge polarity to a plurality ofelectrodes formed on a substrate and spraying the particles whileutilizing a repulsive force operating on the particles, wherein means isemployed for preventing said particles from being turned out of theelectrode domain comprising the plurality of electrodes.
 2. The methodof spraying particles according to claim 1, which comprises providing atleast one dummy electrode outside the electrode domain comprising theplurality of electrodes, and applying, to said dummy electrode, avoltage of the same polarity as the particle charge polarity to therebycontrol the electric field above the peripheral region of the electrodedomain comprising said plurality of electrodes.
 3. The method ofspraying particles according to claim 1 or 2, wherein the voltageapplied to the plurality of electrodes is 500 to 8,000 V.
 4. The methodof spraying particles according to claim 1, 2 or 3, wherein a voltagehaving the same polarity as the particle charge polarity is applied toat least one electrode other than said plurality of electrodes, on thesubstrate in a region at least partly surrounding the periphery of theelectrode domain comprising the plurality of electrodes.
 5. The methodof spraying particles according to claim 1, 2, 3 or 4, wherein theelectrode other than the plurality of electrodes is disposed in a regionsurrounding the periphery of the electrode domain other than anaccessory electrode for voltage application to said plurality ofelectrodes.
 6. The method of spraying particles according to claim 1, 2,3, 4 or 5, wherein the area of the electrode other than the plurality ofelectrodes is larger than the area of any of said plurality ofelectrodes.
 7. The method of spraying particles according to claim 1, 2,3, 4, 5 or 6, wherein the voltage applied to the electrode other thanthe plurality of electrodes is the same as that applied to saidplurality of electrodes.
 8. The method of spraying particles accordingto claim 4, 5, 6 or 7, wherein the electrode other than the plurality ofelectrodes is a solid electrode provided in the periphery region of thesubstrate.
 9. The method of spraying particles according to claim 1, 2,3, 4, 5, 6, 7 or 8, wherein the particles are sprayed by dry method. 10.A method for producing a liquid crystal display device comprisingspraying spacers onto at least one of a first substrate comprising atleast pattern-forming transparent electrodes and having at least onedisplay area and a second substrate to be disposed opposedly above thefirst substrate and filling a liquid crystal into the space between boththe substrates, wherein, in providing accessory electrodes outside thedisplay area and spraying positively or negatively charged spacers ontothe substrate, two or more voltages differing in voltage value areapplied to respective transparent electrodes and a voltage is applied tothe accessory electrodes as well to thereby control the electric fieldgenerated above the transparent electrodes and above the accessoryelectrodes so as to cause selective spacer disposition only in apredetermined transparent electrode gap among the gaps betweenrespective neighboring transparent electrodes.
 11. The method forproducing a liquid crystal display device according to claim 10, whereinthe predetermined transparent electrode gap in which spacers are to bedisposed selectively is provided between the respective transparentelectrodes to which one and the same voltage is applied.
 12. The methodfor producing a liquid crystal display device according to claim 11,wherein, when the spacers are positively charged, the predeterminedtransparent electrode gap in which spacers are to be disposedselectively is provided between the respective transparent electrodes towhich the lowest of the two or more voltages differing in value appliedto the transparent electrodes is applied and, when the spacers arenegatively charged, the electrode gap is provided between the respectivetransparent electrodes to which the highest of the two or more voltagesdiffering in value applied to the transparent electrodes is applied. 13.The method for producing a liquid crystal display device according toclaim 12, wherein the two or more voltages differing in voltage valuewhich are applied to the transparent electrodes have the same polarityas the polarity of the voltage for charging spacers.
 14. The method forproducing a liquid crystal display device according to claim 10, 11, 12or 13, wherein the polarity of the voltage applied to the accessoryelectrodes is selected so that a repulsive force may be exerted on thespacers, when the electric field as formed above the whole region whichcomprises the transparent electrodes, exerts a repulsive force on thespacers, and the polarity of the voltage applied to the accessoryelectrodes is selected so that an attractive force may be exerted on thespacers, when the electric field as formed above the whole region whichcomprises the transparent electrodes, exerts an attractive force on thespacers.
 15. The method for producing a liquid crystal display deviceaccording to claim 14, wherein the voltage applied to the accessoryelectrodes is identical with the voltage exerting the greatest repulsiveor attractive force on the spacers among the two or more voltagesdiffering in voltage value as applied to the transparent electrode. 16.The method for producing a liquid crystal display device according toclaim 10, 11, 12, 13, 14 or 15, wherein the transparent electrodes arestripe-shaped, and the accessory electrodes are disposed in parallelwith the longer sides of the transparent electrodes.
 17. The method forproducing a liquid crystal display device according to claim 10, 11, 12,13, 14, 15 or 16, wherein the accessory electrodes are provided inalmost the same electrode pattern as the transparent electrodes.
 18. Themethod for producing a liquid crystal display device according to claim10, 11, 12, 13, 14, 15 or 16, wherein the accessory electrodes are dummyelectrodes provided for reducing the transparent electrode-due leveldifference.
 19. The method for producing a liquid crystal display deviceaccording to claim 10, 11, 12, 13, 14, 15, 16, 17 or 18, wherein theaccessory electrodes are dummy electrodes not applying display voltagethereto.
 20. A method for producing a liquid crystal display devicecomprising spraying spacers onto at least one of a first substratecomprising at least pattern-forming transparent electrodes and a dummyelectrode and a second substrate to be disposed opposedly above thefirst substrate and filling a liquid crystal into the space between boththe substrates, wherein, in spraying positively or negatively chargedspacers onto the substrate, two or more voltages differing in voltagevalue are applied to respective transparent electrodes and the dummyelectrode as well, the predetermined transparent electrode gaps in whichspacers are to be selectively disposed are provided between respectivetwo neighboring transparent electrodes, the number of transparentelectrodes is even, and the two or more voltages differing in value areapplied in a manner such that when the spacer charge polarity ispositive (+), the lowest of the two or more voltages differing in valueis applied to the respective two neighboring transparent electrodesbetween which spacers are to be disposed in the middle, and when thespacer charge polarity is negative (−), the highest of the two or morevoltages differing in value is applied to the respective two neighboringtransparent electrodes between which spacers are to be disposed in themiddle.
 21. The method for producing a liquid crystal display deviceaccording to claim 20, wherein the voltage applied to a dummy electrodeis within the range of the highest and lowest voltages among the two ormore voltages differing in voltage as applied to the transparentelectrodes.
 22. The method for producing a liquid crystal display deviceaccording to claim 20 or 21, wherein, in cases where the spacer chargepolarity is negative (−), the voltage application to the transparentelectrodes is carried out by providing a common conductor line (A)connected with one of the two ends of each transparent electrode towhich the highest voltage is to be applied, and applying the highestvoltage by means of the conductor line (A), while providing a commonconductor line (B) connected with one end, on the opposite side of theone end mentioned above, of the two ends of each transparent electrodeto which a lower voltage is to be applied, and applying the voltage bymeans of the conductor line (B) and, in cases where the spacer chargepolarity is positive (+), the voltage application to the transparentelectrodes is carried out by providing a common conductor line (A)connected with one of the two ends of each transparent electrode towhich the lowest voltage is to be applied and applying the voltage bymeans of the conductor line (A), while providing a common conductor line(B) connected with one end, on the opposite side of the one endmentioned above, of the two ends of each transparent electrode to whicha higher voltage is to be applied and applying the higher voltage bymeans of the conductor line (B).
 23. The method for producing a liquidcrystal display device according to claim 22, wherein the voltageapplication to a dummy electrode is carried out by connecting the dummyelectrode with either the conductor line (A) or the conductor line (B).24. The method for producing a liquid crystal display device accordingto claim 20, 21 or 22, wherein the voltage application to dummyelectrodes is carried out by connecting all dummy electrodes formed onthe substrate with one another.
 25. A method for producing a liquidcrystal display device comprising spraying spacers onto at least one ofa first substrate comprising at least pattern-forming transparentelectrodes and a dummy electrode and a second substrate to be disposedopposedly above the first substrate and filling a liquid crystal intothe space between both the substrates, wherein, in spraying positivelyor negatively charged spacers onto the substrate, the substrate isdisposed in close contact with an earthed conductive stage, and aconductor is provided in a state electrically insulated from theconductive stage, said conductor being a conductive frame having anopening, said conductor frame being disposed on the periphery of thesubstrate with or without partial overlapping with the substrateperiphery, and wherein a voltage is applied to the transparentelectrodes and the conductive frame.
 26. The method for producing aliquid crystal display device according to claim 25, wherein thesubstrate has a transparent electrode as well as a dummy electrode and,in spraying positively or negatively charged spacers onto the substrate,a voltage is applied to the transparent electrodes, the dummy electrode,and to a conductive frame.
 27. The method for producing a liquid crystaldisplay device according to claim 26, wherein the dummy electrode areconnected with the transparent electrodes and the voltage application tothe dummy electrode is carried out via the conductive frame.
 28. Themethod for producing a liquid crystal display device according to claim27, wherein the voltage applied to the conductive frame is differentfrom the voltage applied to the transparent electrodes.
 29. A method forproducing a liquid crystal display device comprising spraying spacersonto at least one of a first substrate comprising at leastpattern-forming transparent electrodes and an alignment layer and havingat least one display area and a second substrate to be disposedopposedly above the first substrate and filling a liquid crystal intothe space between both the substrates, wherein, in spraying positivelyor negatively charged spacers onto the substrate, the substrate isdisposed in close contact with an earthed conductive stage, a voltagehaving the same polarity as the spacer charge polarity is applied to thetransparent electrodes on the substrate, a conductor is provided,outside the display area, in a state electrically isolated from theconductive stage, and a voltage having the same polarity as the polarityof the voltage applied to the transparent electrodes is applied to theconductor to thereby form almost the same electric field within andwithout the substrate.
 30. The method for producing a liquid crystaldisplay device according to claim 29, wherein the conductor is larger inoutermost size than the substrate, and is a conductive frame having anopening not greater than the substrate size, said conductive frame beingdisposed with or without overlapping with the periphery of thesubstrate, and wherein a voltage of the same polarity as that applied tothe transparent electrodes is applied to the conductive frame.
 31. Themethod for producing a liquid crystal display device according to claim29 or 30, wherein the conductive stage has a size not greater than thesubstrate size but extending to the area outside the parting lines andthe upper surface of the conductive frame is disposed on the almost sameplane as the conductive stage surface or at a level lower than the same.32. The method for producing a liquid crystal display device accordingto claim 29, 30 or 31, wherein the conductive stage has a size notgreater than the substrate size but extending to the area outside theparting lines, the conductive frame is formed so as to extend from thearea outside the parting lines to the outside of the substrate, and thearea occupied by the conductive stage and that by the conductive framein the area outside the parting lines satisfies the relation: [areaoccupied by conductive stage]>[area occupied by conductive frame]. 33.The method for producing a liquid crystal display device according toclaim 29, 30 or 31, wherein the conductive stage has a size not greaterthan the substrate size but extending to the area outside the partinglines and the conductive frame is formed outside the transparentelectrodes without any overlapping with the area outside the partinglines.
 34. The method for producing a liquid crystal display deviceaccording to claim 29, 30 or 31, wherein the conductive stage issubstantially identical in size with the range of occurrence of thetransparent electrodes and the conductive frame is formed by areas whereno transparent electrodes are present.
 35. A method for producing aliquid crystal display device comprising spraying spacers onto at leastone of a first substrate comprising at least pattern-forming transparentelectrodes and an alignment layer and having one or more display areasand a second substrate to be disposed opposedly above the firstsubstrate and filling a liquid crystal into the space between both thesubstrates, wherein, in spraying positively or negatively chargedspacers onto the substrate, the substrate is disposed in close contactwith an earthed conductive stage smaller in size than the substrate toallow the substrate periphery to be apart from the conductive stage, anda voltage of the same polarity as the spacer charge polarity is appliedto the transparent electrodes on the substrate.
 36. The method forproducing a liquid crystal display device according to claim 35, whereinthe substrate onto which spacers are to be sprayed has a black matrixformed thereon, the black matrix is conductive, and the conductive stagecomprises one or more units each smaller in size than the picture frameperiphery of the black matrix of each display area on the substrate. 37.The method for producing a liquid crystal display device according toclaim 35 or 36, wherein the area of contact between the conductive stageand the substrate is not less than 30% of the display area area.
 38. Aparticle sprayer for disposing charged particles selectively on asubstrate having a plurality of electrodes which comprises a nozzle forspraying charged particles onto the substrate, a conductive stage havinga fixed position and serving to hold the substrate onto which chargedparticles are to be sprayed, a plurality of push-up pins for mountingthe substrate on and dismounting the substrate from the conductivestage, a probe for applying a voltage identical in polarity with thecharged particles to a plurality of electrodes on the substrate disposedon the conductive stage, and a conductor is electrically insulated fromthe conductive stage, said conductor being a conductive frame providedwith an opening smaller in size than the substrate, being disposed onthe top of the substrate disposed on the conductive stage, and beingapplied a voltage of the same polarity as the charged particle polaritythereto.
 39. The particle sprayer according to claim 38, wherein theprobe and the conductor move up or down in synchronization with eachother.
 40. The particle sprayer according to claim 38, wherein the probeand the conductor move up or down as an integrated body.
 41. Theparticle sprayer according to claim 38, 39 or 40, wherein the probe,conductor and push-up pins are driven in synchronization by means of asingle driving source.
 42. The particle sprayer according to claim 38,39, 40 or 41, wherein one and the same voltage is applied simultaneouslyto the plurality of electrodes and the conductor.
 43. A liquid crystaldisplay device obtainable by the method of spraying particles accordingto claim 1, 2, 3, 4, 5, 6, 7, 8 or
 9. 44. A liquid crystal displaydevice obtainable by the method for producing a liquid crystal displaydevice according to claim 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20,21, 22, 23 or
 24. 45. A liquid crystal display device obtainable by themethod for producing a liquid crystal display device according to claim25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36 or 37 using the particlesprayer according to claim 38, 39, 40, 41 or 42.